Chemotherapy with preoperative radiotherapy in rectal cancer

Total neoadjuvant therapy in rectal cancer: a network meta-analysis of randomized trials

PURPOSE

To assess the efficacy of total neoadjuvant therapy (TNT) for rectal carcinoma in comparison with conventional chemoradiotherapy (CRT).

METHODS

A systematic review was performed according to the PRISMA guidelines. A Bayesian network meta-analysis was done using NetMetaXL and WinBUGS. This study was registered in PROSPERO on March 3, 2022 (No. CRD-42022307867).

RESULTS

Outcomes of 2,719 patients from 10 randomized trials between 2010 and 2022 were selected. Of these 1,191 (44%) had conventional long-course CRT (50-54 Gy) and capecitabine, 506 (18%) had induction chemotherapy followed by CRT (50-54 Gy) and capecitabine (iTNT), 230 (9%) had long-course CRT (50-54 Gy) followed by consolidation chemotherapy (cTNT), and 792 (29%) undergone modified short-course radiotherapy (25 Gy) with subsequent chemotherapy (mTNT). Total pathologic complete response (pCR) was 20% in the iTNT group, 21% in the mTNT group, 22% in the cTNT group, and 12% in the CRT group. Statistically significant difference in pCR rates was detected when comparing iTNT with CRT (odds ratio [OR], 1.76; 95% credible interval [CrI], 1.06-2.8), mTNT with CRT (OR, 1.90; 95% CrI, 1.25-2.74), and cTNT with CRT groups (OR, 2.54; 95% CrI, 1.26-5.08). No differences were found in R0 resection rates. No significant difference was found in long-term outcomes.

CONCLUSION

The early administration of systemic chemotherapy in the TNT regimen has improved short-term outcomes, though long-term results are underreported. Randomized trials with survival as the endpoint are necessary to evaluate the possible advantages of TNT modes.

Preoperative Radiotherapy with a Simultaneous Integrated Boost Compared to Chemoradiotherapy for cT3-4 Rectal Cancer: Long-Term Results of a Multicenter Randomized Study

BACKGROUND

Preoperative chemoradiotherapy (CRT) is the standard treatment for T3-4 rectal cancer. Here, we compared image-guided and intensity-modulated RT (IG-IMRT) with a simultaneous integrated boost (SIB) (instead of concomitant chemotherapy) versus CRT in a multi-centric randomized trial.

METHODS

cT3-4 rectal cancer patients were randomly assigned to receive preoperative IG-IMRT 46 Gy/23 fractions plus capecitabine 825 mg/m² twice daily (CRT arm) or IG-IMRT 46 Gy/23 fractions with an SIB to the rectal tumor up to a total dose of 55.2 Gy (RTSIB arm).

RESULTS

A total of 174 patients were randomly assigned between April 2010 and May 2014. Grade 3 acute toxicities were 6% and 4% in the CRT and RTSIB arms, respectively. The mean fractional change in SUVmax at 5 weeks after completion of preoperative RT were -55.8% (±24.0%) and -52.9% (±21.6%) for patients in the CRT arm and RTSIB arm, respectively (p = 0.43). The pathologic complete response rate was 24% with CRT compared to 14% with RTSIB. There were no differences in 5-year overall survival (OS), progression-free survival (PFS) or local control (LC).

CONCLUSIONS

The preoperative RTSIB approach was not inferior to CRT in terms of metabolic response, toxicity, OS, PFS and LC, and could be considered an available option for patients unfit for fluorouracil-based CRT.

Prospective evaluation of dose-escalated preoperative concurrent chemo-radiation with image guided-IMRT in locally advanced rectal cancers

Purpose

To analyse the safety and efficacy of neoadjuvant chemoradiation (NACRT) with dose-escalated image-guided intensity modulated radiation therapy (IG-IMRT) in locally advanced (T3/4; T1-4N1-2) rectal cancers (LARCs).

Materials and methods

Twenty patients with the diagnosis of LARC were recruited in this prospective interventional single-arm study treated by IG-IMRT with 45 Gray (Gy) in 25 fractions to elective nodal volumes and 55 Gy in 25 fractions to the gross primary and nodal disease with concurrent capecitabine 825 mg/m2 twice daily on radiotherapy days. Patients underwent total mesorectal excision 6-8 weeks post completion of NACRT followed by adjuvant chemotherapy (Capecitabine and oxaliplatin every 3 weekly for 6-8 cycles). Primary end point was acute toxicity assessment and secondary end points were pathological complete response (pCR) and loco-regional control (LRC).

Results

Clinical T stage was T3:T4 in 19:1 and clinical N0:N1: N2 in 2:7:11 patients, respectively. With a median follow up of 21.2 months (13.8-25.6 months), 18 of 20 (90%) patients received the full course of treatment. Tumour and nodal downstaging was achieved in 78% and 84% of patients, respectively. pCR and overall complete response (defined as pCR and near CR) was achieved in 22.2% and 44.4% of patients, respectively. 2 (10%) patients completed NACRT, and achieved complete clinical response but refused surgery. Adjuvant chemotherapy course was completed by 17/18 (94.5%) patients. Grade 3 toxicities were observed in 2 (10%) patients during NACRT. All patients were disease-free at the time of the last follow up.

Conclusion

Dose-escalation of NACRT therapy with IG-IMRT in LARC patients offers decent rates of pCR and overall response with excellent LRC and acceptable toxicities.

New insights into the responder/nonresponder divide in rectal cancer: Damage-induced Type I IFNs dictate treatment efficacy and can be targeted to enhance radiotherapy

Rectal cancer ranks as the second leading cause of cancer-related deaths. Neoadjuvant therapy for rectal cancer patients often results in individuals that respond well to therapy and those that respond poorly, requiring life-altering excision surgery. It is inadequately understood what dictates this responder/nonresponder divide. Our major aim is to identify what factors in the tumor microenvironment drive a fraction of rectal cancer patients to respond to radiotherapy. We also sought to distinguish potential biomarkers that would indicate a positive response to therapy and design combinatorial therapeutics to enhance radiotherapy efficacy. To address this, we developed an orthotopic murine model of rectal cancer treated with short course radiotherapy that recapitulates the bimodal response observed in the clinic. We utilized a robust combination of transcriptomics and protein analysis to identify differences between responding and nonresponding tumors. Our mouse model recapitulates human disease in which a fraction of tumors respond to radiotherapy (responders) while the majority are nonresponsive. We determined that responding tumors had increased damage-induced cell death, and a unique immune-activation signature associated with tumor-associated macrophages, cancer-associated fibroblasts, and CD8+ T cells. This signature was dependent on radiation-induced increases of Type I Interferons (IFNs). We investigated a therapeutic approach targeting the cGAS/STING pathway and demonstrated improved response rate following radiotherapy. These results suggest that modulating the Type I IFN pathway has the potential to improve radiation therapy efficacy in RC.

Neoadjuvant intermediate-course versus long-course chemoradiotherapy in T3-4/N0+ rectal cancer: Istanbul R-02 phase II randomized study

Radiation therapy (RT) is typically applied using one of two standard approaches for preoperative treatment of resectable locally advanced rectal cancer (LARC): short-course RT (SC-RT) alone or long-course RT (LC-RT) with concurrent fluorouracil (5-FU) chemotherapy. The Phase II single-arm KROG 11-02 study using intermediate-course (IC) (33 Gy (Gray)/10 fr (fraction) with concurrent capecitabine) preoperative chemoradiotherapy (CRT) demonstrated a pathologically complete response rate and a sphincter-sparing rate that were close to those of LC-CRT. The current trial aim to compare the pathological/oncological outcomes, toxicity, and quality of life results of LC-CRT and IC-CRT in cases of LARC. The prescribed dose was 33 Gy/10 fr for the IC-CRT group and 50.4 Gy/28 fr for the LC-CRT group. Concurrent chronomodulated capecitabine (Brunch regimen) 1650 mg/m2/daily chemotherapy treatment was applied in both groups. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Colorectal Cancer Module (EORTC QLQ-CR29) was administered at baseline and at three and six months after CRT. A total of 60 patients with LARC randomized to receive IC-CRT (n = 30) or LC-CRT (n = 30) were included in this phase II randomized trial. No significant difference was noted between groups in terms of pathological outcomes, including pathological response rates (ypT0N0-complete response: 23.3% vs. 16.7%, respectively, and ypT0-2N0-downstaging: 50% for each; p = 0.809) and Dworak score-based pathological tumor regression grade (Grade 4-complete response: 23.3 vs. 16.7%, p = 0.839). The 5-year overall survival (73.3 vs. 86.7%, p = 0.173) rate was also similar. The acute radiation dermatitis (p < 0.001) and any hematological toxicity (p = 0.004) rates were significantly higher in the LC-CRT group, while no significant difference was noted between treatment groups in terms of baseline, third month, and sixth month EORTC QLQ-CR29 scores.

Prognostic Value of the Circumferential Resection Margin After Curative Surgery for Rectal Cancer: A Multicenter Propensity Score-Matched Analysis

BACKGROUND

Recently, positive circumferential resection margin has been found to be an indicator of advanced disease with a high risk of distant recurrence rather than local recurrence.

OBJECTIVE

The study aimed to analyze the prognostic impact of the circumferential resection margin on long-term oncological outcomes in patients with rectal cancer.

DESIGN

This was a multicenter, propensity score-matched (2:1) analysis comparing the positive and negative circumferential resection margins.

SETTINGS

The study was conducted at 5 high-volume centers in Spain.

PATIENTS

Patients who underwent total mesorectal excision with curative intent for middle-low rectal cancer between 2006 and 2014 were included.

MAIN OUTCOME MEASURES

The main outcomes were local recurrence, distant recurrence, overall survival, and disease-free survival.

RESULTS

The unmatched initial cohort consisted of 1599 patients, of whom 4.9% had a positive circumferential resection margin. After matching, 234 patients were included (156 with a negative circumferential margin and 78 with a positive circumferential margin). The median follow-up period was 52.5 (22.0-69.5) months. Local recurrence was significantly higher in patients with a positive circumferential margin (33.3% vs 11.5%; p < 0.001). Distant recurrence was similar in both groups (46.2% vs 42.3%; p = 0.651). There were no statistically significant differences in 5-year overall survival (48.6% vs 43.6%; p = 0.14). Disease-free survival was lower in patients with a positive circumferential margin (36.1% vs 52.3%; p = 0.026).

LIMITATIONS

This study was limited by its retrospective design. The different neoadjuvant treatment options were not included in the propensity score.

CONCLUSIONS

The positive circumferential resection margin was associated with a higher local recurrence rate and worse disease-free survival in comparison with the negative circumferential resection margin. However, the positive circumferential resection margin was not a prognostic indicator of distant recurrence and overall survival. See Video Abstract at http://links.lww.com/DCR/B950 .

VALOR PRONSTICO DEL MARGEN DE RESECCIN CIRCUNFERENCIAL DESPUS DE LA CIRUGA CURATIVA PARA EL CNCER DE RECTO UN ANLISIS MULTICNTRICO EMPAREJADO POR PUNTAJE DE PROPENSIN

ANTECEDENTES:En los últimos años, se ha encontrado que el margen de resección circunferencial positivo es un indicador de enfermedad avanzada con alto riesgo de recurrencia a distancia más que de recurrencia local.OBJETIVO:El objetivo fue analizar el impacto pronóstico del margen de resección circunferencial sobre la recidiva local, a distancia y las tasas de supervivencia en pacientes con cáncer de recto.DISEÑO:Este fue un análisis multicéntrico emparejado por puntaje de propensión 2: 1 que comparó el margen de resección circunferencial positivo y negativo.AJUSTES:El estudio se realizó en 5 centros Españoles de alto volumen.PACIENTES:Se incluyeron pacientes sometidos a escisión total de mesorrecto con intención curativa por cáncer de recto medio-bajo entre 2006-2014. Las características clínicas e histológicas se utilizaron para el emparejamiento.PRINCIPALES MEDIDAS DE RESULTADO:Los resultadoes principales fueron la recurrencia local, la recurrencia a distancia, la supervivencia global y libre de enfermedad.RESULTADOS:La cohorte inicial no emparejada consistió en 1599 pacientes; El 4,9% tuvo un margen de resección circunferencial positivo. Tras el emparejamiento se incluyeron 234 pacientes (156 con margen circunferencial negativo y 78 con margen circunferencial positivo). La mediana del período de seguimiento fue de 52,5 meses (22,0-69,5). La recurrencia local fue significativamente mayor en pacientes con margen circunferencial positivo, 33,3% vs 11,5% [HR 3,2; IC 95%: 1,83-5,43; p < 0,001]. La recidiva a distancia fue similar en ambos grupos (46,2 % frente a 42,3 %) [HR 1,09, IC 95 %: 0,78-1,90; p = 0,651]. No hubo diferencias significativas en la supervivencia global a 5 años (48,6 % frente a 43,6 %) [HR 1,09, IC 95 %: 0,92-1,78; p = 0,14]; La supervivencia libre de enfermedad fue menor en pacientes con margen circunferencial positivo, 36,1% vs 52,3% [HR 1,5; IC 95%: 1,05-2,06; p = 0,026].LIMITACIONES:Este estudio estuvo limitado por el diseño retrospectivo. Las diferentes opciones de tratamientos neoadyuvantes no se han incluido en la puntuación de propensión.CONCLUSIONES:El margen de resección circunferencial positivo se asocia con una mayor tasa de recurrencia local y peor supervivencia libre de enfermedad en comparación con el margen de resección circunferencial negativo. Sin embargo, el margen de resección circunferencial positivo no fue un indicador pronóstico de recidiva a distancia ni de supervivencia global. Consulte el Video del Resumen en http://links.lww.com/DCR/B950 . (Traducción- Dr. Yesenia Rojas-Khalil ).

Does Completeness of the Mesorectal Excision Still Correlate With Local Recurrence?

BACKGROUND

Total mesorectal excision is the standard surgical procedure for rectal cancer treatment. Several studies have shown a close correlation between the prognosis of patients with rectal cancer and the completeness of the mesorectal specimen.

OBJECTIVE

To assess the correlation between macroscopic assessment of mesorectal excision and long-term oncological outcomes.

DESIGN

Retrospective analysis of an Institutional Review Board-approved database.

SETTINGS

Tertiary referral center.

PATIENTS

Patients with rectal cancer who were operated on between March 2016 and October 2019 were classified into 3 groups based on the mesorectal specimen quality: complete, near complete, and incomplete. Only patients with a follow-up of ≥2 years and without signs of preoperative distant disease were included.

MAIN OUTCOME MEASURES

Relationship between total mesorectal excision and local and distant recurrence rates in patients with rectal cancer.

RESULTS

A total of 124 patients (35.5% females) were included in the analysis, with a mean age of 58.1 (SD 12) years and a mean BMI of 26.4 (SD 4.59) kg/m². Neoadjuvant chemoradiation was administered to 71% of patients, whereas 13.7% received total neoadjuvant therapy. Restorative procedures were performed in 107 patients (86.3%), whereas 17 patients (13.7%) underwent abdominoperineal resection. The majority of mesorectal excision specimens (87.09%) were complete or near complete. Local recurrence rates were 6.3% (1/16) in the incomplete and 7.4% (8/108) in the complete/near complete group ( p = 0.86). Metachronous distant metastases occurred in 6 patients (37.5%) in the incomplete group and in 24 patients (22.2%) in the complete/near complete group (p = 0.18). Thus, specimen quality did not appear to impact disease-free survival.

LIMITATIONS

Retrospective, single-center study with relatively short follow-up.

CONCLUSIONS

In the era of a multidisciplinary approach and extensive use of neoadjuvant therapy, macroscopic completeness of total mesorectal excision may not be as valuable a prognosticator as in the past. Larger studies with longer follow-ups are needed to clarify these preliminary findings. See Video Abstract at http://links.lww.com/DCR/C129.

LA INTEGRIDAD DE LA ESCISIN MESORRECTAL TODAVA SE CORRELACIONA CON LA RECURRENCIA LOCAL

ANTECEDENTES:La escisión total desl mesorrecto es el estándar de oro para el tratamiento del cáncer de recto. Varios estudios han demostrado una estrecha correlación entre el pronóstico de los pacientes con cáncer de recto y la integridad espécimen mesorrectal.OBJETIVO:Evaluar la correlación entre la evaluación macroscópica de la escisión mesorrectal y los resultados oncológicos a largo plazo en pacientes con cáncer de recto.DISEÑO:Análisis retrospectivo de una base de datos aprobada por el IRB.ENTORNO CLINICO:El estudio se realizó en un centro de referencia terciario de una sola institución.PACIENTES:Todos los pacientes con cáncer de recto operados entre 3/2016-10/2019. Los pacientes se clasificaron en 3 grupos, según la calidad del espécimen mesorrectal: completo, casi completo e incompleto. Solo se incluyeron pacientes con seguimiento >2 años y sin signos de enfermedad a distancia preoperatoria.PRINCIPALES MEDIDAS DE RESULTADO:Identificar la relación entre la escisión mesorrectal total y las tasas de recurrencia local y a distancia en pacientes con cáncer de recto.RESULTADOS:Se incluyeron 124 pacientes (35,5% mujeres) con una edad media de 58,1 años (DE 12) y un índice de masa corporal medio de 26,4 (DE 4,59). Se administró quimiorradiación neoadyuvante al 71% de los pacientes, mientras que el 13,7% recibió terapia neoadyuvante total. Se realizaron procedimientos de restauración en 107 pacientes (86,3%), mientras que 17 pacientes (13,7%) se sometieron a resección abdominoperineal. La mayoría (87,09%) de los especímenes de escisión mesorrectal fueron completas o casi completas. Las tasas de recurrencia local fueron 1/16 (6,3%) en el grupo incompleto y 8/108 (7,4%) en el grupo completo/casi completo ( p = 0,86). Se produjeron metástasis a distancia metacrónicas en 6 pacientes (37,5%) en el grupo incompleto y 24 (22,2%) en el grupo completo/casi completo ( p = 0,18). Por lo tanto, la calidad del espécimen no pareció afectar la supervivencia libre de enfermedad.LIMITACIONES:Estudio retrospectivo de un solo centro con pequeño número de casos y seguimiento relativamente corto.CONCLUSIÓN:En la era de un enfoque multidisciplinario y el uso extensivo de la terapia neoadyuvante, la integridad macroscópica de la escisión total del mesorrecto, puede no ser un pronóstico tan valioso como en el pasado. Se necesitan estudios más amplios con períodos de seguimiento más prolongados para aclarar estos hallazgos preliminares. Consulte Video Resumen en http://links.lww.com/DCR/C129 . (Traducción-Dr. Fidel Ruiz Healy ).

Does Sarcopenia Predict Local Response Rates After Chemoradiotherapy for Locally Advanced Rectal Cancer?

BACKGROUND

The predictive value of sarcopenia for tumor response to neoadjuvant chemoradiotherapy is unclear.

OBJECTIVE

This study aimed to investigate the association between sarcopenia and pathological tumor regression grade after neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer.

DESIGN

Retrospective cohort study from a prospectively collected database. Univariate logistic regression was performed to assess the association between sarcopenia and tumor response.

SETTINGS

This study was conducted at 2 tertiary care centers.

PATIENTS

Participants were patients undergoing neoadjuvant chemoradiotherapy for locally advanced rectal cancer (T3/4, N0/+) between 2007 and 2018.

INTERVENTION

Sarcopenia was diagnosed using sex-specific cutoffs of lean muscle mass. Using the initial staging CT, lean muscle mass was estimated using the cross-sectional area of the psoas muscle at the level of the third lumbar vertebra, normalized for patient height.

MAIN OUTCOME MEASURES

The primary end point was pathological tumor regression grade, defined as good (tumor regression grade 0/1) vs poor (tumor regression grade 2/3).

RESULTS

The study included 167 patients with locally advanced rectal cancer with a median age of 60 (20-91) years, with 132 in the nonsarcopenia group and 35 in the sarcopenia group. Eighty-nine percent of patients had stage 3 cancer. Nine patients (5.4%) had a complete clinical response, 1 patient did not respond to treatment and opted for nonoperative management, and the remaining 157 patients (94.0%) proceeded to surgery. Pathological data revealed no significant difference between good tumor regression grade patients in the sarcopenia group compared with the nonsarcopenia group. Univariate analysis revealed BMI ≥25 kg/m 2 to be a risk factor for good tumor regression grade ( p = 0.002).

LIMITATIONS

This study was limited by its retrospective design and small sample size.

CONCLUSIONS

Sarcopenia is not a predictor of poor neoadjuvant chemoradiotherapy response in patients with locally advanced rectal cancer. Increasing BMI was associated with good tumor regression grade. Future multicentered studies are warranted to validate this finding. See Video Abstract at http://links.lww.com/DCR/C78 .

LA SARCOPENIA PREDICE LAS TASAS DE RESPUESTA LOCAL DESPUS DE LA QUIMIORRADIOTERAPIA PARA EL CNCER DE RECTO LOCALMENTE AVANZADO

ANTECEDENTES:El valor predictivo de la sarcopenia para la respuesta tumoral a la quimiorradioterapia neoadyuvante no está claro.OBJETIVO:Este estudio investiga la asociación entre la sarcopenia y el grado de regresión tumoral patológica después de la quimiorradioterapia neoadyuvante en pacientes con cáncer de recto localmente avanzado.DISEÑO:Estudio de cohorte retrospectivo a partir de una base de datos recolectada prospectivamente. Se realizó una regresión logística univariante para evaluar la asociación entre la sarcopenia y la respuesta tumoral.ENTORNO CLINICO:Este estudio se realizó en dos centros de atención terciaria.PACIENTES:Pacientes sometidos a quimiorradioterapia neoadyuvante por cáncer de recto localmente avanzado (T3/4, N0/+) entre 2007-2018.INTERVENCIÓNES:La sarcopenia se diagnosticó utilizando puntos de corte de masa muscular magra específicos por género. Utilizando la tomografía computarizada de estadificación inicial, se estimó la masa muscular magra utilizando el área transversal del músculo psoas a nivel de la tercera vértebra lumbar, normalizada para la altura del paciente.PRINCIPALES MEDIDAS DE VALORACIÓN:El criterio principal de valoración fue el grado de regresión tumoral patológica, definido como bueno (grado de regresión tumoral 0/1) frente a malo (grado de regresión tumoral 2/3).RESULTADOS:El estudio incluyó a 167 pacientes con cáncer de recto localmente avanzado con una mediana de edad de 60 años (20-91), 132 en el grupo sin sarcopenia y 35 en el grupo con sarcopenia. Ochenta y nueve por ciento estaban en etapa III. Seis pacientes (5,4%) tuvieron respuesta clínica completa sostenida, un paciente no respondió al tratamiento y optó por manejo conservador, los 157 restantes (94,0%) procedieron a cirugía. Los datos patológicos no revelaron diferencias significativas entre los pacientes con buen grado de regresión tumoral en el grupo de sarcopenia en comparación con el grupo sin sarcopenia. El análisis univariado reveló que un IMC ≥25 kg/m2 era un factor de riesgo para un buen grado de regresión tumoral (p = 0,002).LIMITACIONES:Este estudio estuvo limitado por su diseño retrospectivo y tamaño de muestra pequeño.CONCLUSIÓNES:La sarcopenia no es un predictor de mala respuesta a la quimiorradioterapia neoadyuvante en pacientes con cáncer de recto localmente avanzado. El aumento del IMC se asoció con un buen grado de regresión tumoral. Se justifican futuros estudios multicéntricos para validar este hallazgo. Consulte Video Resumen en http://links.lww.com/DCR/C78 . (Traducción-Dr. Ingrid Melo ).

The Conditioning of Adjuvant Chemotherapy for Stage II and III Rectal Cancer Determined by Postoperative Pathological Characteristics in Romania

The management of locally advanced rectal cancer (LARC) suffered changes thanks to the development of improved surgical procedures, radiation delivery, and chemotherapy. Although treatment options improved individually, the optimal order is still debated. Neoadjuvant chemo-radiotherapy followed by total mesorectal excision (TME) has been the "golden standard" for locally advanced rectal cancer. There is no common ground in international guidelines on the indications of adjuvant chemotherapy (ADJCHT), with differences between the American, European, and Japanese guidelines. This paper studies the preferences of Romanian oncologists in prescribing ADJCHT. We conducted a single-institution, retrospective study of all nonmetastatic, ECOG 0-1 LARC patients staged II-III who underwent TME and were admitted to the Oncology or Radiotherapy Department of Colțea Clinical Hospital, Bucharest between January 2017 and March 2021. A total of 186 patients were included in the study. A positive correlation was found between ADJCHT and each of the following: (y)pT > 2, (y)pN > 0, and the presence of perineural invasion (PNI+). A strong positive correlation was found between ADJCHT and the presence of at least one risk factor: (y)pT > 2, (y)pN > 0, PNI+, lymphovascular invasion, positive margins, or tumor grade > 1. Tumor downstaging decreased the risk of metastases in the first 2 years and was associated with the use of neoadjuvant radiotherapy, while adding neoadjuvant chemotherapy increased the chance of nodal downstaging. ADJCHT practice for LARC in Romania follows either NCCN or ESMO guidelines, at the discretion of the oncologist, due to the lack of national guideline.

Long-term outcomes and failure patterns after laparoscopic intersphincteric resection in ultralow rectal cancers

BACKGROUND

Intersphincteric resection (ISR), the ultimate anus-preserving technique for ultralow rectal cancers, is an alternative to abdominoperineal resection (APR). The failure patterns and risk factors for local recurrence and distant metastasis remain controversial and require further investigation.

AIM

To investigate the long-term outcomes and failure patterns after laparoscopic ISR in ultralow rectal cancers.

METHODS

Patients who underwent laparoscopic ISR (LsISR) at Peking University First Hospital between January 2012 and December 2020 were retrospectively reviewed. Correlation analysis was performed using the Chi-square or Pearson's correlation test. Prognostic factors for overall survival (OS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were analyzed using Cox regression.

RESULTS

We enrolled 368 patients with a median follow-up of 42 mo. Local recurrence and distant metastasis occurred in 13 (3.5%) and 42 (11.4%) cases, respectively. The 3-year OS, LRFS, and DMFS rates were 91.3%, 97.1%, and 90.1%, respectively. Multivariate analyses revealed that LRFS was associated with positive lymph node status [hazard ratio (HR) = 5.411, 95% confidence interval (CI) = 1.413-20.722, P = 0.014] and poor differentiation (HR = 3.739, 95%CI: 1.171-11.937, P = 0.026), whereas the independent prognostic factors for DMFS were positive lymph node status (HR = 2.445, 95%CI: 1.272-4.698, P = 0.007) and (y)pT3 stage (HR = 2.741, 95%CI: 1.225-6.137, P = 0.014).

CONCLUSION

This study confirmed the oncological safety of LsISR for ultralow rectal cancer. Poor differentiation, (y)pT3 stage, and lymph node metastasis are independent risk factors for treatment failure after LsISR, and thus patients with these factors should be carefully managed with optimal neoadjuvant therapy, and for patients with a high risk of local recurrence (N + or poor differentiation), extended radical resection (such as APR instead of ISR) may be more effective.

Pattern of care for re-irradiation in locally recurrent rectal cancer: a national survey on behalf of the AIRO gastrointestinal tumors study group

PURPOSE

Radical resection (R0) represents the best curative treatment for local recurrence (LR) rectal cancer. Re-irradiation (re-RT) can increase the rate of R0 resection. Currently, there is a lack of guidelines on Re-RT for LR rectal cancer. The Italian Association of Radiation and clinical oncology for gastrointestinal tumors (AIRO-GI) study group released a national survey to investigate the current clinical practice of external beam radiation therapy in these patients.

MATERIAL AND METHODS

In February 2021, the survey was designed and distributed to members of the GI working group. The questionnaire consisted of 40 questions regarding center characteristics, clinical indications, doses, and treatment techniques of re-RT for LR rectal cancer.

RESULTS

A total of 37 questionnaires were collected. Re-RT was reported as an option for neoadjuvant treatment in resectable and unresectable disease by 55% and 75% of respondents, respectively. Long-course treatment with 30-40 Gy (1.8-2 Gy/die, 1.2 Gy bid) and hypofractionated regimen of 30-35 Gy in 5 fractions were used in most centers. A total dose of 90-100 Gy as EqD2 dose (α/β = 5 Gy) was delivered by 46% of the respondents considering the previous treatment. Modern conformal techniques and daily image-guided radiation therapy protocols were used in 94% of centers.

CONCLUSION

Our survey showed that re-RT treatment is performed with advanced technology that allow a good management of LR rectal cancer. Significant variations were observed in terms of dose and fractionation, highlighting the need for a consensus on a common treatment strategy that could be validated in prospective studies.

Radiosensitizing Effects of Irinotecan versus Oxaliplatin Alone and in Combination with 5-Fluorouracil on Human Colorectal Cancer Cells

To date, oxaliplatin and irinotecan are used in combination with 5-flourouracil (5-FU) for metastatic colorectal cancer. In this study it was tested whether oxaliplatin and irinotecan and their combinations with 5-FU have an enhanced effect when treated simultaneously with ionizing radiation. In addition, it should be compared whether one combination therapy is more effective than the other. Colorectal cancer cells (HT-29) were treated with irinotecan or oxaliplatin, both alone and in combination with 5-FU, and subsequently irradiated. The cell growth, metabolic activity and proliferation of cells were investigated, and the clonogenic survival was determined. Furthermore, the assessment of radiation-induced DNA damage and the influence of the drugs and their combinations on DNA damage repair was investigated. Treatment with irinotecan or oxaliplatin in combination with 5-FU inhibited proliferation and metabolic activity as well as clonogenic survival and the DNA damage repair capacity of the tumor cells. The comparison of oxaliplatin and irinotecan with simultaneous irradiation showed the same effect of both drugs. When oxaliplatin or irinotecan was combined with 5-FU, tumor cell survival was significantly lower than with monotherapy; however, there was no superiority of either combination regimen. Our results have shown that the combination of 5-FU and irinotecan is as effective as the combination of 5-FU with oxaliplatin. Therefore, our data support the use of FOLFIRI as a radiosensitizer.

pCR and 2-Year Disease-Free Survival: A Combination of the Two Endpoints as a New Classification for Locally Advanced Rectal Cancer Patients-An Updated Pooled Analysis of Eleven International Randomized Trials

LARC is managed by multimodal treatments whose intensity can be highly modulated. In this context, we need surrogate endpoints to help predict long-term outcomes and better personalize treatments. A previous study identified 2yDFS as a stronger predictor of OS than pCR in LARC patients undergoing neoadjuvant RT. The aim of this pooled analysis was to assess the role of pCR and 2yDFS as surrogate endpoints for OS in a larger cohort. The pooled and subgroup analyses were performed on large rectal cancer randomized trial cohorts who received long-course RT. Our analysis focused on the evaluation of OS in relation to the pCR and 2-year disease status. A total of 4600 patients were analyzed. Four groups were identified according to intermediate outcomes: 12% had both pCR and 2yDFS (the better); 67% achieved 2yDFS but not pCR (the good); 1% had pCR but not 2yDFS; and 20% had neither pCR nor 2yDFS (the bad). The pCR and 2yDFS were favorably associated with OS in the univariate analysis, and 2yDFS maintained a statistically significant association in the multivariate analysis independently of the pCR status. The combination of the pCR and 2yDFS results in a strong predictor of OS, whereas failure to achieve 2yDFS carries a poor prognosis regardless of the pCR status. This new stratification of LARC patients could help design predictive models where the combination of 2yDFS and pCR should be employed as the primary outcome.

Local versus radical surgery for early rectal cancer with or without neoadjuvant or adjuvant therapy

BACKGROUND

Total mesorectal excision is the standard of care for stage I rectal cancer. Despite major advances and increasing enthusiasm for modern endoscopic local excision (LE), uncertainty remains regarding its oncologic equivalence and safety relative to radical resection (RR).

OBJECTIVES

To assess the oncologic, operative, and functional outcomes of modern endoscopic LE compared to RR surgery in adults with stage I rectal cancer.

SEARCH METHODS

We searched CENTRAL, Ovid MEDLINE, Ovid Embase, Web of Science - Science Citation Index Expanded (1900 to present), four trial registers (ClinicalTrials.gov, ISRCTN registry, the WHO International Clinical Trials Registry Platform, and the National Cancer Institute Clinical Trials database), two thesis and proceedings databases, and relevant scientific societies' publications in February 2022. We performed handsearching and reference checking and contacted study authors of ongoing trials to identify additional studies.

SELECTION CRITERIA

We searched for randomized controlled trials (RCTs) in people with stage I rectal cancer comparing any modern LE techniques to any RR techniques with or without the use of neo/adjuvant chemoradiotherapy (CRT).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We calculated hazard ratios (HR) and standard errors for time-to-event data and risk ratios for dichotomous outcomes, using generic inverse variance and random-effects methods. We regrouped surgical complications from the included studies into major and minor according to the standard Clavien-Dindo classification. We assessed the certainty of evidence using the GRADE framework.

MAIN RESULTS

Four RCTs were included in data synthesis with a combined total of 266 participants with stage I rectal cancer (T1-2N0M0), if not stated otherwise. Surgery was performed in university hospital settings. The mean age of participants was above 60, and median follow-up ranged from 17.5 months to 9.6 years. Regarding the use of co-interventions, one study used neoadjuvant CRT in all participants (T2 cancers); one study used short-course radiotherapy in the LE group (T1-T2 cancers); one study used adjuvant CRT selectively in high-risk patients undergoing RR (T1-T2 cancers); and the fourth study did not use any CRT (T1 cancers). We assessed the overall risk of bias as high for oncologic and morbidity outcomes across studies. All studies had at least one key domain with a high risk of bias. None of the studies reported separate outcomes for T1 versus T2 or for high-risk features. Low-certainty evidence suggests that RR may result in an improvement in disease-free survival compared to LE (3 trials, 212 participants; HR 1.96, 95% confidence interval (CI) 0.91 to 4.24). This would translate into a three-year disease-recurrence risk of 27% (95% CI 14 to 50%) versus 15% after LE and RR, respectively. Regarding sphincter function, only one study provided objective results and reported short-term deterioration in stool frequency, flatulence, incontinence, abdominal pain, and embarrassment about bowel function in the RR group. At three years, the LE group had superiority in overall stool frequency, embarrassment about bowel function, and diarrhea. Local excision may have little to no effect on cancer-related survival compared to RR (3 trials, 207 participants; HR 1.42, 95% CI 0.60 to 3.33; very low-certainty evidence). We did not pool studies for local recurrence, but the included studies individually reported comparable local recurrence rates for LE and RR (low-certainty evidence). It is unclear if the risk of major postoperative complications may be lower with LE compared with RR (risk ratio 0.53, 95% CI 0.22 to 1.28; low-certainty evidence; corresponding to 5.8% (95% CI 2.4% to 14.1%) risk for LE versus 11% for RR). Moderate-certainty evidence shows that the risk of minor postoperative complications is probably lower after LE (risk ratio 0.48, 95% CI 0.27 to 0.85); corresponding to an absolute risk of 14% (95% CI 8% to 26%) for LE compared to 30.1% for RR. One study reported an 11% rate of temporary stoma after LE versus 82% in the RR group. Another study reported a 46% rate of temporary or permanent stomas after RR and none after LE. The evidence is uncertain about the effect of LE compared with RR on quality of life. Only one study reported standard quality of life function, in favor of LE, with a 90% or greater probability of superiority in overall quality of life, role, social, and emotional functions, body image, and health anxiety. Other studies reported a significantly shorter postoperative period to oral intake, bowel movement, and off-bed activities in the LE group.

AUTHORS' CONCLUSIONS

Based on low-certainty evidence, LE may decrease disease-free survival in early rectal cancer. Very low-certainty evidence suggests that LE may have little to no effect on cancer-related survival compared to RR for the treatment of stage I rectal cancer. Based on low-certainty evidence, it is unclear if LE may have a lower major complication rate, but probably causes a large reduction in minor complication rate. Limited data based on one study suggest better sphincter function, quality of life, or genitourinary function after LE. Limitations exist with respect to the applicability of these findings. We identified only four eligible studies with a low number of total participants, subjecting the results to imprecision. Risk of bias had a serious impact on the quality of evidence. More RCTs are needed to answer our review question with greater certainty and to compare local and distant metastasis rates. Data on important patient outcomes such as sphincter function and quality of life are very limited. Results of currently ongoing trials will likely impact the results of this review. Future trials should accurately report and compare outcomes according to the stage and high-risk features of rectal tumors, and evaluate quality of life, sphincter, and genitourinary outcomes. The role of neoadjuvant or adjuvant therapy as an emerging co-intervention for improving oncologic outcomes after LE needs to be further defined.

Local Excision Versus Total Mesorectal Excision After Favourable Response to Neoadjuvant Therapy in Low Rectal Cancer: a Multi-centre Experience

The gold standard surgical management of curable rectal cancer is proctectomy with total mesorectal excision. Adding preoperative radiotherapy improved local control. The promising results of neoadjuvant chemoradiotherapy raised the hopes for conservative, yet oncologically safe management, probably using local excision technique. This study is a prospective comparative phase III study, where 46 rectal cancer patients were recruited from patients attending Oncology Centre of Mansoura University and Queen Alexandra Hospital Portsmouth University Hospital NHS with a median follow-up 36 months. The two recruited groups were as follows: group (A), 18 patients who underwent conventional radical surgery by TME; and group (B), 28 patients who underwent trans-anal endoscopic local excision. Patients of resectable low rectal cancer (below 10 cms from anal verge) with sphincter saving procedures were included: cT1-T3N0. The median operative time for LE was 120 min versus 300 in TME (p < 0.001), and median blood loss was 20 ml versus 100 ml in LE and TME, respectively (p < 0.001). Median hospital stay was 3.5 days versus 6.5 days (p = 0.009). No statistically significant difference in median DFS (64.2 months for LE versus 63.2 months for TME, p = 0.85) and median OS (72.9 months for LE versus 76.3 months for TME, p = 0.43). No statistically significant difference in LARS scores and QoL was observed between LE and TME (p = 0.798, p = 0.799). LE seems a good alternative to radical rectal resection in carefully selected responders to neoadjuvant therapy after thorough pre-operative evaluation, planning and patient counselling.

Lateral Lymph Node Size and Tumor Distance From Anal Verge Accurately Predict Positive Lateral Pelvic Lymph Nodes in Rectal Cancer: A Multi-Institutional Retrospective Cohort Study

BACKGROUND

Lateral pelvic lymph node dissection improves oncological outcomes in rectal cancer patients with suspected lateral pelvic lymph node metastasis. However, the indication for this procedure remains unclear.

OBJECTIVE

This study aimed to identify the predictive factors for lateral lymph node metastasis and the indications for lateral pelvic lymph node dissection.

DESIGN

A multi-institutional retrospective study.

SETTINGS

This study was conducted at 3 university hospitals.

PATIENTS

This study involved 105 patients with locally advanced mid/low rectal cancer and clinically suspected lateral pelvic lymph node metastasis who underwent total mesorectal excision with lateral pelvic lymph node dissection between 2015 and 2020.

MAIN OUTCOME MEASURES

Indications were set using lateral pelvic lymph node metastasis-associated preoperative factors.

RESULTS

Among 105 patients, 36 (34.3%) had pathologically confirmed lateral pelvic lymph node metastasis and 77 (73.3%) underwent preoperative chemoradiation. Tumors located within 5 cm distance from the anal verge ( p = 0.02) and initial node size ≥ 6 mm ( p = 0.001) were significant predictors of lateral pelvic lymph node metastasis. The sensitivity was 100% (36/36) with a cutoff of 6 mm for the initial node size and 94.4% (34/36) with a cutoff of 8 mm for the initial node size. When using initial node size cutoffs of 8 mm for anal verge-to-tumor distance of >5 cm and 6 mm for anal verge-to-tumor distance of ≤5 cm, the sensitivity of lateral pelvic lymph node metastasis was found to be 100%.

LIMITATIONS

The retrospective design and small sample size were the limitations of this study.

CONCLUSION

Initial node size and tumor height were significant predictors of lateral pelvic lymph node metastasis. This study proposed that an initial node size of ≥8 mm with an anal verge-to-tumor distance of >5 cm and ≥6 mm with an anal verge-to-tumor distance of ≤5 cm are optimal indications for lateral pelvic lymph node dissection in rectal cancer. See Video Abstract at http://links.lww.com/DCR/C101 .

EL TAMAO DEL GANGLIO LINFTICO LATERAL Y LA DISTANCIA DEL TUMOR DESDE EL BORDE ANAL PREDICEN CON PRECISIN LOS GANGLIOS LINFTICOS PLVICOS LATERALES POSITIVOS EN EL CNCER DE RECTO UN ESTUDIO DE COHORTE RETROSPECTIVO MULTIINSTITUCIONAL

ANTECEDENTES:La disección de los ganglios linfáticos pélvicos laterales mejora los resultados oncológicos en pacientes con cáncer de recto con sospecha de metástasis en los ganglios linfáticos pélvicos laterales. Sin embargo, la indicación de este procedimiento sigue sin estar clara.OBJETIVO:Nuestro objetivo fue identificar los factores predictivos de la metástasis de los ganglios linfáticos laterales y las indicaciones para la disección de los ganglios linfáticos pélvicos laterales.DISEÑO:Estudio retrospectivo multiinstitucional.AJUSTES:Este estudio se realizó en tres hospitales universitarios.PACIENTES:Este estudio involucró a 105 pacientes con cáncer de recto medio/bajo localmente avanzado y sospecha clínica de metástasis en los ganglios linfáticos pélvicos laterales que se sometieron a una escisión mesorrectal total con disección de los ganglios linfáticos pélvicos laterales entre 2015 y 2020.PRINCIPALES MEDIDAS DE RESULTADO:Las indicaciones se establecieron utilizando los factores preoperatorios asociados con la metástasis de los ganglios linfáticos pélvicos laterales.RESULTADOS:Entre 105 pacientes, 36 (34,3%) tenían metástasis en los ganglios linfáticos pélvicos laterales confirmada patológicamente y 77 (73,3%) se sometieron a quimiorradiación preoperatoria. Los tumores ubicados dentro de los 5 cm desde el borde anal ( p = 0,02) y el tamaño inicial del ganglio ( p = 0,001) fueron predictores significativos de metástasis en los ganglios linfáticos pélvicos laterales. La sensibilidad fue del 100 % (36/36), con un punto de corte de 6 mm para el tamaño inicial del ganglio, seguido de 8 mm para el tamaño inicial del ganglio (94,4%, 34/36). Cuando se utilizó un tamaño de corte inicial del ganglio de 8 mm para una distancia entre el borde anal y el tumor >5 cm y 6 mm para una distancia entre el borde anal y el tumor ≤5 cm, la sensibilidad de la metástasis en los ganglios linfáticos pélvicos laterales fue del 100 %.LIMITACIONES:El diseño retrospectivo y el pequeño tamaño de la muestra.CONCLUSIONES:El tamaño inicial del ganglio y la altura del tumor fueron predictores significativos de metástasis en los ganglios linfáticos pélvicos laterales. Este estudio propuso que un tamaño de ganglio inicial de ≥8 mm con un tumor a >5 cm del margen anal y ≥6 mm con un tumor a ≤5 cm del margen anal son indicaciones óptimas para la disección de los ganglios linfáticos pélvicos laterales en el cáncer de recto. Consulte Video Resumen en http://links.lww.com/DCR/C101 . (Traducción-Dr. Yolanda Colorado ).

Robotic and laparoscopic salvage lateral pelvic node dissection for the treatment of recurrent rectal cancer

BACKGROUND

The lateral pelvic sidewall is a major site of local recurrence after radical resection of rectal cancer. Salvage lateral pelvic node dissection (LPND) may be the only way to eliminate recurrent lateral pelvic nodes (LPNs). This study aimed to describe the technical details of robotic and laparoscopic salvage LPND and assess the short-term clinical and oncological outcomes in patients with recurrent LPNs who underwent salvage LPND by a minimally invasive approach for curative intent.

METHODS

Between September 2010 and 2019, 36 patients who underwent salvage surgery for LPN recurrence were retrospectively analyzed from a prospectively maintained database. Patients' characteristics, index operation, MRI findings, and perioperative and pathological outcomes were analyzed.

RESULTS

Eleven and 14 patients underwent robotic and laparoscopic salvage LPND, respectively. Eight patients (32.0%) underwent a combined salvage operation for resectable extra-pelvic sidewall metastases. There were four cases of open-conversion during the laparoscopic approach due to uncontrolled bleeding of iliac vessels. In these patients, metastatic LPNs were suspected of iliac vessel invasion and were found to be larger in size (median 15 mm; range 12-20) than that in patients who underwent successful LPND using the minimally invasive approach (median 10 mm; range 5-20). The median number of metastatic LPNs and harvested LPNs was 1 (range 0-3) and 6 (range 1-16), respectively. Six patients (24.0%) experienced postoperative complications including lymphoceles and voiding difficulties. During the follow-up (median 44.6 months; range 24.0-87.7), eight patients developed recurrences, mainly the lung and para-aortic lymph nodes, and one patient developed pelvic sidewall recurrence after laparoscopic salvage LPND. The 3-year disease-free survival and overall survival after salvage LPND were 66.4% and 79.2%, respectively.

CONCLUSIONS

Robotic and laparoscopic salvage LPND for recurrent LPNs are safe and feasible with favorable short-term surgical outcomes. However, the surgical approach should be carefully chosen in patients with large-sized and invasive recurrent LPNs.

Determining the optimal interval between neoadjuvant radiochemotherapy and surgery in rectal cancer: a retrospective cohort study

INTRODUCTION

In locally advanced rectal cancer, the optimal interval between completion of neoadjuvant radiochemotherapy (RT-ChT) and surgical resection remains unclear due to contradictory data on the benefits of extending this interval. Therefore, the aim of this retrospective study was to determine the impact of this interval on outcomes in patients treated for rectal cancer at our center.

METHODS

We retrospectively reviewed 382 consecutive patients treated for stage II/III rectal cancer between October 1, 2012, and December 31, 2017. We evaluated four different cut-off points (56, 63, 70, and 77 days) to determine which had the greatest impact on treatment outcomes.

RESULTS

The median time between completion of RT-ChT and surgery was 67.2 days (range, 28-294). Intervals > 8 weeks (56 days) were associated with worse therapeutic outcomes. Specifically, an interval ≥ 77 days was associated with a significant decrease in overall survival (OS; 84% vs. 70%; p = 0.004), which is why we selected this interval for the comparative analysis. Several outcome variables were significantly better in the short interval (< 77 days) group, including margin involvement (5.2% vs. 13.9%; p = 0.01), sphincter preservation (78% vs. 59.3%; p = 0.003), and distant dissemination (22.6% vs. 32.5%; p = 0.04). No significant between-group differences were found in complete/nearly complete response rates (19.2% vs. 24.4%; p = 0.3). Time to surgery was statistically significant on both the univariate and multivariate analyses.

CONCLUSIONS

Our findings suggest that surgery should not be delayed more than 8 weeks (56 days) after neoadjuvant treatment. An interval > 8 weeks should only be considered in patients who demonstrate a good response to neoadjuvant RT-ChT.

Identification of patients with locally advanced rectal cancer eligible for neoadjuvant chemotherapy alone: Results of a retrospective study

BACKGROUND AND OBJECTIVES

Neoadjuvant chemotherapy (nCT) appears in a few clinical studies as an alternative to neoadjuvant chemoradiation (nCRT) in selected patients with locally advanced rectal cancer (LARC). We aimed to compare the clinical outcomes of nCT with or without nCRT in patients with LARC and to identify patients who may be suitable for nCT alone.

MATERIALS AND METHODS

A total of 155 patients with LARC who received neoadjuvant treatment (NT) were retrospectively analysed from January 2016 to June 2021. The patients were divided into two groups: nCRT (n = 101) and nCT (n = 54). More patients with locally advanced disease (cT4, cN+ and magnetic resonance imaging-detected mesorectal fascia [mrMRF] positive [+]) were found in the nCRT group. Patients in the nCRT group received a dose of 50 Gy/25 Fx irradiation with concurrent capecitabine, and the median number of nCT cycles was two. In the nCT group, the median number of cycles was four.

RESULTS

The median follow-up duration was 30 months. The pathologic complete response (pCR) rate in the nCRT group was significantly higher than that in the nCT group (17.5% vs. 5.6%, p = 0.047). A significant difference was observed in the locoregional recurrence rate (LRR); 6.9% in the nCRT group and 16.7% in the nCT group (p = 0.011). Among patients with initial mrMRF (+) status, the LRR in the nCRT group was significantly lower than that in the nCT group (6.1% vs. 20%, p = 0.007), but not in patients with initial mrMRF negative (-) (10.5% in each group, p = 0.647). Compared with the nCT group, a lower LRR was observed in patients in the nCRT group with initial mrMRF (+) converted to mrMRF (-) after NT (5.3% vs. 23%, p = 0.009). No significant difference was observed between the two groups regarding acute toxicity and overall and progression-free survivals. Multivariate analysis showed that nCRT and ypN stage were independent prognostic factors for the development of LRR.

CONCLUSION

Patients with initial mrMRF (-) may be suitable for nCT alone. However, patients with initial mrMRF (+) converted to mrMRF (-) after nCT are still at high risk of LRR, and radiotherapy is recommended. Prospective studies are required to confirm these findings.

New Opportunities for Minimizing Toxicity in Rectal Cancer Management

Advances in multimodal management of locally advanced rectal cancer (LARC), consisting of preoperative chemotherapy and/or radiotherapy followed by surgery with or without adjuvant chemotherapy, have improved local disease control and patient survival but are associated with significant risk for acute and long-term morbidity. Recently published trials, evaluating treatment dose intensification via the addition of preoperative induction or consolidation chemotherapy (total neoadjuvant therapy [TNT]), have demonstrated improved tumor response rates while maintaining acceptable toxicity. In addition, TNT has led to an increased number of patients achieving a clinical complete response and thus eligible to pursue a nonoperative, organ-preserving, watch and wait approach, thereby avoiding toxicities associated with surgery, such as bowel dysfunction and stoma-related complications. Ongoing trials using immune checkpoint inhibitors in patients with mismatch repair-deficient tumors suggest that this subgroup of patients with LARC could potentially be treated with immunotherapy alone, sparing them the toxicity associated with preoperative treatment and surgery. However, the majority of rectal cancers are mismatch repair-proficient and less responsive to immune checkpoint inhibitors and require multimodal management. The synergy noted in preclinical studies between immunotherapy and radiotherapy on immunogenic tumor cell death has led to the design of ongoing clinical trials that explore the benefit of combining radiotherapy, chemotherapy, and immunotherapy (mainly of immune checkpoint inhibitors) and aim to increase the number of patients eligible for organ preservation.

Surgical outcomes in pelvic exenteration for advanced and recurrent malignancy: a high volume single institution experience

PURPOSE

Pelvic exenteration remains the only curative treatment for advanced pelvic malignancies. However, identification of predictive factors for successful surgical outcomes is still a controversial issue at present time.

METHODS

This retrospective study included data from all adult patients with colorectal or anal advanced pelvic malignancy registered for pelvic exenteration at the Leon Berard Cancer Center (Lyon, France). The primary endpoint was the surgical outcomes and aimed to define the predictive factors for postoperative complications. Secondary endpoints included overall survival and progression free survival in patients having experienced pelvic exenteration (PE).

RESULTS

Data from 141 patients with locally advanced tumor (N = 81) or recurrent malignancies (N = 60) diagnosed between May 1994 and November 2018 were collected. The median age was 63.3 years (95%CI 20.0-92.0). Malignancies included different locations (rectal: 69.5%, left colon: 17.0% and anal: 13.5%). Posterior pelvectomy was the most frequent surgery (81.6%). The median length of hospital stay was 23.3 days (95%CI 3.0-82.0). The major complication rate at 30 days was 24.8% and 38.1% at 90 days. The median overall survival was 54.5 months (95%CI 41.5-104.1) and the median PFS was 34.5 months (95%CI 19.6-NA).

CONCLUSION

In selected patients, pelvic exenteration is associated with good surgical and survival outcomes.

FOSL2 promotes intertumoral infiltration of T cells and increases pathological complete response rates in locally advanced rectal cancer patients

The outcome of neoadjuvant chemoradiotherapy (nCRT) remains highly unpredictable for individuals with locally advanced rectal cancer (LARC). We set out to characterize effective biomarkers that promote a pathological complete response (pCR). We quantified the abundances of 6483 high-confidence proteins in pre-nCRT biopsies of 58 LARC patients from two hospitals with pressure cycling technology (PCT)-assisted pulse data-independent acquisition (PulseDIA) mass spectrometry. Compared with non-pCR patients, pCR patients achieved long-term disease-free survival (DFS) and had higher tumor immune infiltration, especially CD8+ T cell infiltration, before nCRT. FOSL2 was selected as the candidate biomarker for predicting pCR and was found to be significantly upregulated in pCR patients, which was verified in another 54 pre-nCRT biopsies of LARC patients by immunohistochemistry. FOSL2 expression was able to predict pCR by multiple reaction monitoring (MRM) with high efficiency (Area under curve (AUC) = 0.939, specificity = 1.000, sensitivity = 0.850), and high FOSL2 expression was associated with long-term DFS (p = 0.044). When treated with simulated nCRT, FOSL2 sufficiency resulted in more significant inhibition of cell proliferation, and more significant promotion of cell cycle arrest and cell apoptosis. Moreover, CXCL10 secretion with abnormal cytosolic dsDNA accumulation was found in FOSL2-wildtype (FOSL2-WT) tumor cells over nCRT, which might elevate CD8+ T-cell infiltration and CD8+ T-cell-mediated cytotoxicity to promote nCRT-induced antitumor immunity. Our study revealed proteomic profiles in LARC patients before nCRT and highlighted immune activation in the tumors of patients who achieved pCR. We identified FOSL2 as a promising biomarker to predict pCR and promote long-term DFS by contributing to CD8+ T-cell infiltration.

Robotic Lateral Pelvic Lymph Node Dissection Could Harvest More Lateral Pelvic Lymph Nodes over Laparoscopic Approach for Mid-to-Low Rectal Cancer: A Multi-Institutional Retrospective Cohort Study

Lateral pelvic lymph node dissection (LPND) is a technically demanding procedure. This study aimed to compare the short-term outcomes of laparoscopic and robotic LPNDs. This multi-institutional retrospective study included 108 consecutive patients who underwent laparoscopic or robotic total mesorectal excision with LPND for locally advanced rectal cancer. There were 74 patients in the laparoscopic and 34 in the robotic groups. The median operation time was longer in the robotic group than in the laparoscopic group (353 vs. 275 min, p < 0.001). No patients underwent conversion to open surgery in either group. Pathological LPN metastases were observed in 24 and 8 patients in the laparoscopic and robotic groups, respectively (p = 0.347). Although the number of harvested mesorectal lymph nodes was similar (15.5 vs. 15.0, p = 0.968), the number of harvested LPNs was higher in the robotic than in the laparoscopic group (7.0 vs. 5.0, p = 0.004). Postoperative complications and length of hospital stay were similar (robotic vs. laparoscopic, 35.3% and 7 days vs. 37.8% and 7 days, respectively). Both laparoscopic and robotic LPND are safe and feasible for locally advanced rectal cancers, but robotic LPND showed more harvested lateral lymph node than laparoscopic LPND.

The effect of nutritional interventions in acute radiation-induced diarrhoea in patients with primary pelvic cancer: A systematic review

Acute radiation-induced diarrhoea (RID) is a well-known side effect of external radiation therapy for pelvic cancer. Acute RID is an unresolved clinical problem in approximately 80% of patients. We investigated the effect of nutritional interventions on acute RID in patients with pelvic cancer treated with curative radiotherapy. A search was conducted using PubMed, Embase.com, CINAHL, and Cochrane Library, from 1 January 2005 until 10 October 2022. We included randomised controlled trials or prospective observational studies. Eleven of the 21 identified studies had low quality of evidence, mainly because of low patient numbers distributed among several cancer diagnoses, and non-systematic assessment of acute RID. Interventions included probiotics (n = 6), prebiotics (n = 6), glutamine (n = 4), and others (n = 5). Five studies, of which two provided high quality evidence, showed that probiotics improved acute RID. Future well-designed studies investigating the effects of probiotics on acute RID are warranted. PROSPERO ID: CRD42020209499).

Adjuvant chemotherapy does not improve cancer-specific survival for pathologic stage II/III rectal adenocarcinoma after neoadjuvant chemoradiotherapy and surgery: evidence based on long-term survival analysis from SEER data

PURPOSE

Adjuvant chemotherapy is controversial in rectal cancer, especially after neoadjuvant chemoradiotherapy (NCRT). This retrospective study aims at evaluating adjuvant chemotherapy's long-term survival benefits in stage II and stage III rectal adenocarcinoma (RC).

METHODS

This study obtained data from the Surveillance, Epidemiology, and End Results (SEER) database registered between 2010 and 2015. The survival analyses used the Kaplan-Meier method and were compared by log-rank test. The factors that affect survival outcomes were analyzed by univariate and multivariate Cox regression. The propensity score matching (1:4) was used to ensure the balance of variables between different groups.

RESULTS

The median follow-up time for overall patients was 64 months. The 5-year overall survival (OS) and cancer-specific survival (CSS) rates were 51.3% and 67.4% in the adjuvant chemotherapy (-) group and 73.9% and 79.6% in the adjuvant chemotherapy ( +) group (p < 0.001, p = 0.002). However, subgroup analysis showed adjuvant chemotherapy after NCRT improved the 5-year OS but not CSS rates in stage II and stage III RC (p = 0.003, p = 0.004; p = 0.29, p = 0.3). Univariate and multivariate analyses found adjuvant chemotherapy after NCRT was an independent prognosis factor of OS but not CSS (HR 0.8, 95%CI 0.7-0.92, p < 0.001; p = 0.276).

CONCLUSION

The survival benefits from adjuvant chemotherapy were associated with the status of NCRT for pathological stage II and III RC. For patients who did not receive NCRT, adjuvant chemotherapy is needed to significantly improve long-term survival rates. However, adjuvant chemotherapy after NCRT did not significantly improve long-term CSS.

Forecasting Individual Patients' Best Time for Surgery in Colon-Rectal Cancer by Tumor Regression during and after Neoadjuvant Radiochemotherapy

The standard treatment of locally advanced rectal cancer is neoadjuvant chemoradiotherapy before surgery. For those patients experiencing a complete clinical response after the treatment, a watch-and-wait strategy with close monitoring may be practicable. In this respect, the identification of biomarkers of the response to therapy is extremely important. Many mathematical models have been developed or used to describe tumor growth, such as Gompertz's Law and the Logistic Law. Here we show that the parameters of those macroscopic growth laws, obtained by fitting the tumor evolution during and immediately after therapy, are a useful tool for evaluating the best time for surgery in this type of cancer. A limited number of experimental observations of the tumor volume regression, during and after the neoadjuvant doses, permits a reliable evaluation of a specific patient response (partial or complete recovery) for a later time, and one can evaluate a modification of the scheduled treatment, following a watch-and-wait approach or an early or late surgery. Neoadjuvant chemoradiotherapy effects can be quantitatively described by applying Gompertz's Law and the Logistic Law to estimate tumor growth by monitoring patients at regular intervals. We show a quantitative difference in macroscopic parameters between partial and complete response patients, reliable for estimating the treatment effects and best time for surgery.

Preoperative chemoradiotherapy using tegafur/uracil, oral leucovorin, and irinotecan (TEGAFIRI) followed by oxaliplatin-based chemotherapy as total neoadjuvant therapy for locally advanced rectal cancer: the study protocol for a phase II trial

BACKGROUND

Total neoadjuvant therapy (TNT) is a novel treatment strategy that is an alternative to preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). However, an optimal protocol for TNT has not yet been established. The present study will be an open-label, single-arm, single-center trial to develop a new protocol.

METHODS

Thirty LARC patients at high risk of distant metastasis will receive CRT consisting of long-course radiation, concurrent with tegafur/uracil, oral leucovorin, irinotecan (TEGAFIRI), followed by mFOLFOX-6 or CAPOX before undergoing surgery.

DISCUSSION

Since previous findings showed a high percentage of grade 3-4 adverse events with the TEGAFIRI regimen for CRT and TNT, the primary outcome of this study will be safety and feasibility. Our regimen for CRT consists of the biweekly administration of irinotecan for good patient compliance. The novel combination approach of this treatment may improve the long-term outcomes of LARC.

TRIAL REGISTRATION

Japan Registry of Clinical Trials jRCTs031210660.

Particle beam therapy for pelvic recurrence of colorectal cancer: a registry data analysis in Japan and a systematic review

The aim of this study was to investigate the efficacy and safety of particle beam therapy (PBT) with proton or carbon ion beam for pelvic recurrence of colorectal cancer (PRCC) by comparing the clinical outcomes of a dataset of prospectively enrolled patients for PBT with those from the literature, which were collected by a systematic review of external X-ray radiotherapy (XRT) and PBT. Patients with PRCC treated at 14 domestic facilities between May 2016 and June 2019 and entered the database for prospective observational follow-up were analyzed. The registry data analyzed included 159 PRCC patients treated with PBT of whom 126 (79%) were treated with carbon ion radiation therapy (CIRT). The 3-year overall survival and local control rate were 81.8 and 76.4%, respectively. Among these PRCC patients, 5.7% had Grade 3 or higher toxicity. Systematic search of PubMed and Cochrane databases published from January 2000 to September 2020 resulted in 409 abstracts for the primary selection. Twelve studies fulfilled the inclusion criteria. With one additional publication, 13 studies were selected for qualitative analysis, including 9 on XRT and 4 on PBT. There were nine XRT studies, which included six on 3D conformal radiotherapy and three on stereotactic body radiation therapy, and four PBT studies included three on CIRT and one on proton therapy. A pilot meta-analysis using literatures with median survival time extractable over a 20-month observation period suggested that PBT, especially CIRT, may be a promising treatment option for PRCC not amenable to curative resection.

MRI radiomics signature to predict lymph node metastasis after neoadjuvant chemoradiation therapy in locally advanced rectal cancer

PURPOSE

To investigative the performance of MRI-radiomics analysis derived from T2WI and apparent diffusion coefficients (ADC) images before and after neoadjuvant chemoradiation therapy (nCRT) separately or simultaneously for predicting post-nCRT lymph node status in patients with locally advanced rectal cancer (LARC). MATERIALS AND METHODS: Eighty-three patients (training cohort, n = 57; validation cohort, n = 26) with LARC between June 2017 and December 2022 were retrospectively enrolled. All the radiomics features were extracted from volume of interest on T2WI and ADC images from baseline and post-nCRT MRI. Delta-radiomics features were defined as the difference between radiomics features before and after nCRT. Seven clinical-radiomics models were constructed by combining the most predictive radiomics signatures and clinical parameters selected from support vector machine. Receiver operating characteristic curve (ROC) was used to evaluate the performance of models. The optimum model-based LNM was applied to assess 5-years disease-free survival (DFS) using Kaplan-Meier analysis. The end point was clinical or radiological locoregional recurrence or distant metastasis during postoperative follow-up.

RESULTS

Clinical-deltaADC radiomics combined model presented good performance for predicting post-CRT LNM in the training (AUC = 0.895,95%CI:0.838-0.953) and validation cohort (AUC = 0.900,95%CI:0.771-1.000). Clinical-deltaADC radiomics-postT2WI radiomics combined model also showed good performances (AUC = 0.913,95%CI:0.838-0.953) in the training and (AUC = 0.912,95%CI:0.771-1.000) validation cohort. As for subgroup analysis, clinical-deltaADC radiomics combined model showed good performance predicting LNM in ypT0-T2 (AUC = 0.827;95%CI:0.649-1.000) and ypT3-T4 stage (AUC = 0.934;95%CI:0.864-1.000). In ypT0-T2 stage, clinical-deltaADC radiomics combined model-based LNM could assess 5-years DFS (P = 0.030).

CONCLUSION

Clinical-deltaADC radiomics combined model could predict post-nCRT LNM, and this combined model-based LNM was associated with 5-years DFS in ypT0-T2 stage.

New insights into the responder/nonresponder divide in rectal cancer: Damage-induced Type I IFNs dictate treatment efficacy and can be targeted to enhance radiotherapy

Rectal cancer ranks as the second leading cause of cancer-related deaths. Neoadjuvant therapy for rectal cancer patients often results in individuals that respond well to therapy and those that respond poorly, requiring life-altering excision surgery. It is inadequately understood what dictates this responder/nonresponder divide. Our major aim is to identify what factors in the tumor microenvironment drive a fraction of rectal cancer patients to respond to radiotherapy. We also sought to distinguish potential biomarkers that would indicate a positive response to therapy and design combinatorial therapeutics to enhance radiotherapy efficacy. To address this, we developed an orthotopic murine model of rectal cancer treated with short course radiotherapy that recapitulates the bimodal response observed in the clinic. We utilized a robust combination of transcriptomics and protein analysis to identify differences between responding and nonresponding tumors. Our mouse model recapitulates human disease in which a fraction of tumors respond to radiotherapy (responders) while the majority are nonresponsive. We determined that responding tumors had increased damage-induced cell death, and a unique immune-activation signature associated with tumor-associated macrophages, cancer-associated fibroblasts, and CD8 + T cells. This signature was dependent on radiation-induced increases of Type I interferons (IFNs). We investigated a therapeutic approach targeting the cGAS/STING pathway and demonstrated improved response rate following radiotherapy. These results suggest that modulating the Type I IFN pathway has the potential to improve radiation therapy efficacy in RC.

Current status of locally advanced rectal cancer therapy and future prospects

Rectal cancer treatment has been evolving ever since the beginning of the 20th century. Surgery was originally the only available method regardless of the extent of tumor invasion or nodal involvement status. Total mesorectal excision was established as the standard procedure in the early 1990s. Advances in the utilization of radiation for rectal cancer led to the addition of radiotherapy (RT) combined with chemotherapy to the postoperative treatment algorithm. The promising results of the Swedish short-course preoperative RT set the basis for a number of large randomized trials investigating the efficacy of neoadjuvant RT or chemoradiotherapy (CRT) for advanced rectal cancer. Both short-course RT and long-course preoperative CRT compared favorably to adjuvant treatment and became the standard of choice for patients with extramural invasion or lymph node involvement. Recently, the focus of clinical research has been shifted towards total neoadjuvant therapy (TNT), delivering the whole course of RT and chemotherapy before surgery, and showing good tolerance and encouraging efficacy. Although targeted therapies haven't displayed a benefit in the neoadjuvant setting, preliminary evidence suggests impressive efficacy of immunotherapy in rectal carcinomas with mismatch-repair deficiency. In this review, we provide an in-depth critical overview of all significant randomized trials that have shaped the current treatment guidelines for locally advanced rectal cancer and discuss future trends for the treatment of this common malignancy.

Efficacy of concurrent radiotherapy in patients with locally advanced rectal cancer and synchronous metastasis receiving systemic therapy

BACKGROUND

Neoadjuvant chemoradiotherapy followed by total mesorectal excision is the standard treatment for patients with nonmetastatic locally advanced rectal cancer (LARC). However, for patients with LARC and synchronous metastasis, the optimal treatment strategy and sequence remain inconclusive. In the present study, we evaluated the efficacy and safety of concurrent radiotherapy in patients with de novo metastatic rectal cancer who received chemotherapy and targeted therapy.

METHODS

We retrospectively reviewed the data of 63 patients with LARC and synchronous metastasis who received intensive therapy at the study hospital between April 2015 and November 2018. The included patients were divided into two groups: RT-CT, those who received systemic chemotherapy with targeted therapy and concurrent radiotherapy (for primary rectal cancer), and CT, those who received only systemic chemotherapy with targeted therapy.

RESULTS

Treatment response was better in the RT-CT group than in the CT group. The rate of primary tumor resection (PTR) was higher in the RT-CT group than in the CT group (71.4% and 42.9%, respectively; P = .0286). The RT-CT group exhibited considerably longer local recurrence-free survival (P = .0453) and progression-free survival (PFS; from 13.3 to 22.5 months) than did the CT group (P = .0091); however, the groups did not differ in terms of overall survival (OS; P = .49). Adverse events were almost similar between the groups, except frequent diarrhea, the prevalence of which was higher in the RT-CT group than in the CT group (59.5% and 23.8%, respectively; P = .0075).

CONCLUSIONS

In the era of biologics, radiotherapy may increase the resectability of primary rectal tumors, reducing the risk of locoregional failure and prolonging PFS. Concurrent pelvic radiotherapy may not substantially improve OS, which is indicated by metastasis. Hence, the resection of the distant metastases may be essential for improving long-term OS. To further determine the efficacy of concurrent radiotherapy, additional prospective, randomized studies must combine preoperative pelvic radiotherapy with PTR and metastectomy to treat patients with stage IV LARC.

Impact of a digital surgical workflow including Digital Device Briefing Tool on morbidity and mortality in a patient population undergoing primary stapled colorectal anastomosis for benign or malignant colorectal disease: protocol for a multicentre prospective cohort study

INTRODUCTION

With growing emphasis on surgical safety, it appears fundamental to assess the safety of colorectal resection involving primary stapled anastomosis. Surgical stapling devices can considerably foster patient safety in colorectal surgery, but their misuse or malfunction encompass a unique risk of postoperative complications. The Digital Device Briefing Tool (DDBT) is a digital cognitive aid developed to enhance safe use of the Ethicon circular stapling device during colorectal resection. The purpose of this study is to evaluate how a digital operative workflow, including DDBT, compared with routine surgical care, affects morbidity and mortality in patients undergoing left-sided colorectal resection with primary stapled colorectal anastomosis for colorectal cancer or benign disease.

METHODS AND ANALYSIS

A multicentre, prospective cohort study will be conducted at five certified academic colorectal centres in Germany. It compares a non-digital with a Johnson & Johnson digital solution (Surgical Process Institute Deutschland (SPI))-guided operative workflow in patients undergoing left hemicolectomy, sigmoidectomy, anterior rectal resection and Hartmann reversal procedure. The sample size is set at 528 cases in total, divided into 3 groups (a non-digital and two SPI-guided workflow cohorts, with and without DDBT) in a ratio of 1:1:1, with 176 patients each. The primary endpoint is a composite outcome comprising the overall rate of surgical complications, including death, during hospitalisation and within the first 30 days after colorectal resection. Secondary endpoints include operating time, length of hospital stay and 30-day hospital readmission rate.

ETHICS AND DISSEMINATION

This study will be performed in line with the Declaration of Helsinki. The ethics committee of the Charité-University Medicine Berlin, Germany, approved the study (No: 22-0277-EA2/060/22). Study Investigators will obtain written informed consent from each patient before a patient may participate in this study. The study results will be submitted to an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

DRKS00029682.

Identification of hub genes and potential molecular mechanisms related to radiotherapy sensitivity in rectal cancer based on multiple datasets

BACKGROUND

Radiotherapy resistance is the main cause of low tumor regression for locally advanced rectum adenocarcinoma (READ). The biomarkers correlated to radiotherapy sensitivity and potential molecular mechanisms have not been completely elucidated.

METHODS

A mRNA expression profile and a gene expression dataset of READ (GSE35452) were acquired from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Differentially expressed genes (DEGs) between radiotherapy responder and non-responder of READ were screened out. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis for DEGs were performed. Random survival forest analysis was used to identified hub genes by randomForestSRC package. Based on CIBERSORT algorithm, Genomics of Drug Sensitivity in Cancer (GDSC) database, Gene set variation analysis (GSVA), enrichment analysis (GSEA), nomogram, motif enrichment and non-coding RNA network analyses, the associations between hub genes and immune cell infiltration, drug sensitivity, specific signaling pathways, prognosis prediction and TF - miRNA regulatory and ceRNA network were investigated. The expressions of hub genes in clinical samples were displayed with the online Human Protein Atlas (HPA).

RESULTS

In total, 544 up-regulated and 575 down-regulated DEGs in READ were enrolled. Among that, three hubs including PLAGL2, ZNF337 and ALG10 were identified. These three hub genes were significantly associated with tumor immune infiltration, different immune-related genes and sensitivity of chemotherapeutic drugs. Also, they were correlated with the expression of various disease-related genes. In addition, GSVA and GSEA analysis revealed that different expression levels of PLAGL2, ZNF337 and ALG10 affected various signaling pathways related to disease progression. A nomogram and calibration curves based on three hub genes showed excellent prognosis predictive performance. And then, a regulatory network of transcription factor (ZBTB6) - mRNA (PLAGL2) and a ceRNA network of miRNA (has-miR-133b) - lncRNA were established. Finally, the results from HPA online database demonstrated the protein expression levels of PLAGL2, ZNF337 and ALG10 varied widely in READ patients.

CONCLUSION

These findings indicated that up-regulation of PLAGL2, ZNF337 and ALG10 in READ associated with radiotherapy response and involved in multiple process of cellular biology in tumor. They might be potential predictive biomarkers for radiotherapy sensitivity and prognosis for READ.

Neoadjuvant immunotherapy for colorectal cancer: Right regimens, right patients, right directions?

Neoadjuvant chemoradiotherapy (NACRT) or chemotherapy (NACT) followed by radical resection and then adjuvant therapy is considered the optimal treatment model for locally advanced colorectal cancer (LACRC). A recent total neoadjuvant therapy (TNT) strategy further improved the tumour regression rate preoperatively and reduced local-regional recurrence in locally advanced rectal cancer (LARC). However, distant metastasis was still high, and little overall survival benefit was obtained from these preoperative treatment models. According to mismatch repair protein expression, MSI-H/dMMR and non-MSI-H/pMMR statuses were defined in colorectal cancer (CRC) patients. Due to the special features of biologics in MSI-H/dMMR CRC patients, this subgroup of patients achieved little treatment efficacy from chemoradiotherapy but benefited from immune checkpoint inhibitors (ICIs). The KEYNOTE-177 trial observed favourable survival outcomes in metastatic CRC patients treated with one-line pembrolizumab with tolerable toxicity. Given the better systemic immune function, increased antigenic exposure, and improved long-term memory induction before surgery, neoadjuvant ICI (NAICI) treatment was proposed. The NICHE trial pioneered the use of NAICI treatment in LACRC, and recent reports from several phase II studies demonstrated satisfactory tumour downsizing in CRC. Preclinical rationales and preliminary early-phase human trials reveal the feasibility of NAICI therapy and the therapeutic efficacy provided by this treatment model. Better tumour regression before surgery also increases the possibility of organ preservation for low LARC. However, the optimal treatment strategy and effective biomarker identification for beneficiary selection remain unknown, and potential pitfalls exist, including tumour progression during neoadjuvant treatment due to drug resistance and surgery delay. Given these foundations and questions, further phase II or III trials with large samples need to be conducted to explore the right regimens for the right patients.

The value of post-operative chemotherapy after chemoradiotherapy in patients with high-risk locally advanced rectal cancer-results from the RAPIDO trial

BACKGROUND

Pre-operative chemoradiotherapy (CRT) rather than radiotherapy (RT) has resulted in fewer locoregional recurrences (LRRs), but no decrease in distant metastasis (DM) rate for patients with locally advanced rectal cancer (LARC). In many countries, patients receive post-operative chemotherapy (pCT) to improve oncological outcomes. We investigated the value of pCT after pre-operative CRT in the RAPIDO trial.

PATIENTS AND METHODS

Patients were randomised between experimental (short-course RT, chemotherapy and surgery) and standard-of-care treatment (CRT, surgery and pCT depending on hospital policy). In this substudy, we compared curatively resected patients from the standard-of-care group who received pCT (pCT+ group) with those who did not (pCT- group). Subsequently, patients from the pCT+ group who received at least 75% of the prescribed chemotherapy cycles (pCT ≥75% group) were compared with patients who did not receive pCT (pCT-/- group). By propensity score stratification (PSS), we adjusted for the following unbalanced confounders: age, clinical extramural vascular invasion, distance to the anal verge, ypT stage, ypN stage, residual tumour, serious adverse event (SAE) and/or readmission within 6 weeks after surgery and SAE related to pre-operative CRT. Cumulative probability of disease-free survival (DFS), DM, LRR and overall survival (OS) was analysed by Cox regression.

RESULTS

In total, 396/452 patients had a curative resection. The number of patients in the pCT+, pCT >75%, pCT- and pCT-/- groups was 184, 112, 154 and 149, respectively. The PSS-adjusted analyses for all endpoints demonstrated hazard ratios between approximately 0.7 and 0.8 (pCT+ versus pCT-), and 0.5 and 0.8 (pCT ≥75% versus pCT-/-). However, all 95% confidence intervals included 1.

CONCLUSIONS

These data suggest a benefit of pCT after pre-operative CRT for patients with high-risk LARC, with approximately 20%-25% improvement in DFS and OS and 20%-25% risk reductions in DM and LRR. Compliance with pCT additionally reduces or improves all endpoints by 10%-20%. However, differences are not statistically significant.

Essential updates 2020/2021: Advancing precision medicine for comprehensive rectal cancer treatment

In the paradigm shift related to rectal cancer treatment, we have to understand a variety of new emerging topics to provide appropriate treatment for individual patients as precision medicine. However, information on surgery, genomic medicine, and pharmacotherapy is highly specialized and subdivided, creating a barrier to achieving thorough knowledge. In this review, we summarize the perspective for rectal cancer treatment and management from the current standard-of-care to the latest findings to help optimize treatment strategy.

Risk and location of distant metastases in patients with locally advanced rectal cancer after total neoadjuvant treatment or chemoradiotherapy in the RAPIDO trial

INTRODUCTION

Although optimising rectal cancer treatment has reduced local recurrence rates, many patients develop distant metastases (DM). The current study investigated whether a total neoadjuvant treatment strategy influences the development, location, and timing of metastases in patients diagnosed with high-risk locally advanced rectal cancer included in the Rectal cancer And Pre-operative Induction therapy followed by Dedicated Operation (RAPIDO) trial.

MATERIAL AND METHODS

Patients were randomly assigned to short-course radiotherapy followed by 18 weeks of CAPOX or FOLFOX4 before surgery (EXP), or long-course chemoradiotherapy with optional postoperative chemotherapy (SC-G). Assessments for metastatic disease were performed pre- and post-treatment, during surgery, and 6, 12, 24, 36, and 60 months postoperatively. From randomisation, differences in the occurrence of DM and first site of metastasis were evaluated.

RESULTS

In total, 462 patients were evaluated in the EXP and 450 patients in the SC-G groups. The cumulative probability of DM at 5 years after randomisation was 23% [95% CI 19-27] and 30% [95% CI 26-35] (HR 0.72 [95% CI 0.56-0.93]; P = 0.011) in the EXP and SC-G, respectively. The median time to DM was 1.4 (EXP) and 1.3 years (SC-G). After diagnosis of DM, median survival was 2.6 years [95% CI 2.0-3.1] in the EXP and 3.2 years [95% CI 2.3-4.1] in the SC-G groups (HR 1.39 [95% CI 1.01-1.92]; P = 0.04). First occurrence of DM was most often in the lungs (60/462 [13%] EXP and 55/450 [12%] SC-G) or the liver (40/462 [9%] EXP and 69/450 [15%] SC-G). A hospital policy of postoperative chemotherapy did not influence the development of DM.

CONCLUSIONS

Compared to long-course chemoradiotherapy, total neoadjuvant treatment with short-course radiotherapy and chemotherapy significantly decreased the occurrence of metastases, particularly liver metastases.

Long-term results of a phase 2 study of neoadjuvant chemotherapy with molecularly targeted agents for locally advanced rectal cancer

BACKGROUND

We previously reported the feasibility and efficacy of neoadjuvant chemotherapy without radiotherapy for locally advanced rectal cancer. Here, we report the results of a long-term follow-up study.

METHODS

This was a multi-institutional, prospective phase 2 study of patients with locally advanced rectal cancer. Patients received neoadjuvant chemotherapy with molecularly targeted agents before undergoing total mesorectal excision. Six cycles of modified FOLFOX (mFOLFOX6) with bevacizumab were administered to KRAS-mutant patients, and mFOLFOX6 with cetuximab was administered to KRAS-wild-type patients. Here, we report the secondary end points of overall survival, relapse-free survival, and local recurrence rate.

RESULTS

Sixty patients were enrolled in this study. R0 resection was achieved in 98.3% (59/60) patients, and pathological complete response was achieved in 16.7% (10/60) patients. After a median follow-up of 5.4 years, the 5 year overall survival was 81.6%, the 5 year relapse-free survival was 71.7%, and the 5 year local recurrence rate was 12.6%. None of the patients who achieved pathological complete response developed recurrence within 5 years.

CONCLUSIONS

The use of molecularly targeted agents in the neoadjuvant setting for locally advanced rectal cancer has an acceptable prognosis.

A systematic review and network meta-analysis of randomised controlled trials comparing neoadjuvant treatment strategies for stage II and III rectal cancer

AIM

Multiple neoadjuvant therapy strategies have been used and compared for rectal cancer and there has been no true consensus as to the optimal neoadjuvant therapy regimen. The aim is to identify and compare the neoadjuvant therapies available for stage II and III rectal cancer.

DESIGN

A systematic literature review was performed, from inception to August 2022, of the following databases: MEDLINE, EMBASE, Science Citation Index Expanded, Cochrane Library. Only randomized controlled trials comparing neoadjuvant therapies for stage II and III rectal cancer were considered. Stata was used to draw network plots, and a Bayesian network meta-analysis was conducted through models utilizing the Markov Chain Monte Carlo method in WinBUGS.

RESULTS

A total of 58 articles were included based on 41 randomised controlled trials, reporting on 12,404 participants that underwent 15 neoadjuvant treatment regimens. No significant difference was identified between treatments for major or total postoperative complications, anastomotic leak rates, or sphincter-saving surgery. Straight to surgery (STS) ranked as best treatment for preoperative toxicity but ranked worst treatment for positive resection margins and complete response. STS had significantly increased positive resection margins compared to long-course chemoradiotherapy with short-wait (LCCRT-SW) or long-wait (LCCRT-LW) to surgery, or short-course radiotherapy with short-wait (SCRT-SW) or immediate surgery (SCRT-IS). LCCRT-SW or LCCRT-LW resulted in significantly increased complete response rates compared to STS. LCCRT-LW significantly improved 2-year overall survival compared to STS, SCRT-IS, SCRT-SW. Total neoadjuvant therapy regimes with short-course radiotherapy followed by consolidation chemotherapy (SCRT-CT-SW), induction chemotherapy followed by long-course chemoradiotherapy (CT-LCCRT-S), long-course chemoradiotherapy followed by consolidation chemotherapy (LCCRT-CT-S), significantly improved positive resection margins, complete response, and disease-free survival compared to STS. Chemotherapy with monoclonal antibodies followed by long-course chemoradiotherapy (CT+MAB-LCCRT+MAB-S) significantly improved complete response and positive resection margins compared to STS, and 2-year disease-free survival compared to STS, SCRT-IS, SCRT-SW, SCRT-CT-SW, LCCRT-SW, LCCRT-LW. CT+MAB-LCCRT+MAB-S ranked as best treatment for disease-free survival and overall survival.

CONCLUSIONS

Conventional neoadjuvant therapies with short-course radiation or long-course chemoradiotherapy have oncological benefits compared to no neoadjuvant therapy without increasing perioperative complication rates. Prolonged wait to surgery may improve oncological outcomes. Total neoadjuvant therapies provide additional benefits in terms of complete response, positive resection margins, and disease-free survival. Monoclonal antibody therapy may further improve oncological outcomes but currently is only applicable to a small subgroup of patients and requires further validation.

Total Neoadjuvant Therapy Significantly Increases Complete Clinical Response

BACKGROUND

Increased experience with total neoadjuvant therapy for rectal cancer suggests significantly more tumor regression and increased rates of complete clinical response as measured by pathological complete response and clinical complete response.

OBJECTIVE

This study aimed to assess outcomes after total neoadjuvant therapy versus standard neoadjuvant chemoradiotherapy for patients with locally advanced rectal cancer.

DESIGN

This is a retrospective cohort study.

SETTINGS

A database of patients with rectal cancer from 2015 to 2019 at a large integrated health care system was reviewed.

PATIENTS

Demographics of the 2 groups revealed no significant difference in clinical stage or patient characteristics. Of 465 patients, 66 patients underwent total neoadjuvant therapy and 399 underwent standard neoadjuvant chemoradiotherapy. Fifty-six patients underwent consolidation chemotherapy, and 10 underwent induction chemotherapy.

MAIN OUTCOME MEASURES

Complete clinical response, disease-free survival, proctectomy-free survival, and organ preservation rates were the main outcome measures.

RESULTS

Complete clinical response was achieved in 36 patients (58.1%) versus 59 patients (14.8%; p < 0.001), favoring the total neoadjuvant therapy group. Three-year overall survival was similar between groups (85.6% standard neoadjuvant chemoradiotherapy versus 86.0% total neoadjuvant therapy). Three-year distant metastasis-free survival was 67.4% in the total neoadjuvant therapy group compared to 77.7% in the standard neoadjuvant chemoradiotherapy group. Three-year proctectomy-free survival was 44% in the total neoadjuvant therapy group compared to 6% in the standard neoadjuvant chemoradiotherapy group. Twenty-two patients (37.3% of complete clinical responders) in the standard neoadjuvant chemoradiotherapy group elected to pursue organ preservation, whereas 31 patients (86.1% of complete clinical responders) from the total neoadjuvant therapy group chose organ preservation.

LIMITATIONS

This study is limited by its retrospective nature with a shorter follow-up of 3 years.

CONCLUSIONS

Total neoadjuvant therapy for rectal cancer significantly increased complete clinical response. This allowed patients to have greater organ preservation with no significant difference in overall survival or disease control. See Video Abstract at http://links.lww.com/DCR/B934 .

LA TERAPIA NEOADYUVANTE TOTAL AUMENTA SIGNIFICATIVAMENTE LA RESPUESTA CLNICA COMPLETA

ANTECEDENTES:La mayor experiencia con la terapia neoadyuvante total para el cáncer de recto sugiere una regresión tumoral significativamente mayor y mayores tasas de respuesta clínica completa, medidas por respuesta patológica completa y respuesta clínica completa.OBJETIVO:Este estudio evaluó los resultados después de la terapia neoadyuvante total versus la quimiorradioterapia neoadyuvante estándar para pacientes con cáncer de recto localmente avanzado.DISEÑO:Este es un estudio de cohorte retrospectivo.ESCENARIO:Se revisó una base de datos de pacientes con cáncer de recto de 2015 a 2019 en un sistema de salud integrado grande.PACIENTES:La demografía de los dos grupos no revela diferencias significativas en el estadio clínico o las características de los pacientes. De 465 pacientes, 66 pacientes recibieron terapia neoadyuvante total y 399 quimiorradioterapia neoadyuvante estándar. Cincuenta y seis se sometieron a quimioterapia de consolidación mientras que 10 pacientes a quimioterapia de inducción.PRINCIPALES MEDIDAS DE RESULTADO:Se midieron la respuesta clínica completa, la sobrevida libre de enfermedad, la sobrevida libre de proctectomía y las tasas de preservación de órgano.RESULTADOS:Se logró una respuesta clínica completa en 36 pacientes (58.1 %) frente a 59 pacientes (14.8 %) (p < 0,001) a favor del grupo de terapia neoadyuvante total. La sobrevida general a tres años fue similar entre los grupos (85.6 % quimiorradioterapia neoadyuvante estándar frente a 86.0 % terapia neoadyuvante total). La sobrevida libre de metástasis a distancia a los tres años fue del 67.4 % en el grupo de terapia neoadyuvante total y del 77.7 % en el grupo de quimiorradioterapia neoadyuvante estándar. La sobrevida sin proctectomía a los tres años fue del 44 % en el grupo de terapia neoadyuvante total frente al 6 % en el grupo de quimiorradioterapia neoadyuvante estándar. Veintidós pacientes (37.3 % con respuesta clínica completa) en el grupo de quimiorradioterapia neoadyuvante estándar optaron por la preservación de órgano, mientras que 31 pacientes (86.1 % respuesta clínica completa) del grupo de terapia neoadyuvante total eligieron la preservación de órgano.LIMITACIONES:Este estudio es un estudio retrospectivo con un seguimiento más corto de 3 años.CONCLUSIONES:La terapia neoadyuvante total para el cáncer de recto aumentó significativamente la respuesta clínica completa. Esto permitió a los pacientes tener una mayor preservación de órgano sin diferencias significativas en la sobrevida general o el control de la enfermedad. Consulte Video Resumen en http://links.lww.com/DCR/B934 . (Traducción-Dr. Jorge Silva Velazco ).

Expression Levels of GHRH-Receptor, pAkt and Hsp90 Predict 10-Year Overall Survival in Patients with Locally Advanced Rectal Cancer

Background: Rectal cancer constitutes nearly one-third of all colorectal cancer diagnoses, and certain clinical and molecular markers have been studied as potential prognosticators of patient survival. The main objective of our study was to investigate the relationship between the expression intensities of certain proteins, including growth-hormone-releasing hormone receptor (GHRH-R), Hsp90, Hsp16.2, p-Akt and SOUL, in specimens of locally advanced rectal cancer patients, as well as the time to metastasis and 10-year overall survival (OS) rates. We also investigated whether these outcome measures were associated with the presence of other clinical parameters. Methods: In total, 109 patients were investigated retrospectively. Samples of pretreatment tumors were stained for the proteins GHRH-R, Hsp90, Hsp16.2, p-Akt and SOUL using immunhistochemistry methods. Kaplan–Meier curves were used to show the relationships between the intensity of expression of biomarkers, clinical parameters, the time to metastasis and the 10-year OS rate. Results: High levels of p-Akt, GHRH-R and Hsp90 were associated with a significantly decreased 10-year OS rate (p = 0.001, p = 0.000, p = 0.004, respectively) and high expression levels of p-Akt and GHRH-R were correlated with a significantly shorter time to metastasis. Tumors localized in the lower third of the rectum were linked to both a significantly longer time to metastasis and an improved 10-year OS rate. Conclusions: Hsp 90, pAkt and GHRH-R as well as the lower-third localization of the tumor were predictive of the 10-year OS rate in locally advanced rectal cancer patients. The GHRH-R and Hsp90 expression levels were independent prognosticators of OS. Our results imply that GHRH-R could play a particularly important role both as a molecular biomarker and as a target for the anticancer treatment of advanced rectal cancer.

The impact of adjuvant chemotherapy on survival in mucinous and non-mucinous rectal adenocarcinoma patients after TME surgery

INTRODUCTION

The value of adjuvant chemotherapy for rectal cancer patients is debated and varies in different subgroups. One such subgroup is mucinous adenocarcinoma (MAC), which is more treatment resistant compared to non-mucinous adenocarcinoma (NMAC). To date, mucinous histology is not taken into account when deciding on adjuvant treatment strategy. This is the first study to exclusively include patients with rectal cancer, then separate MAC and NMAC and compare the survival in patients that had or did not have adjuvant chemotherapy.

MATERIAL AND METHODS

The study included retrospective register data from 365 Swedish patients with stage II-IV rectal adenocarcinoma, 56 patients with MAC and 309 patients with NMAC. All patients were considered curative, had surgery with total mesorectal excision in 2004-2013, and were followed up until death or 2021.

RESULTS

Patients with MAC that had adjuvant chemotherapy had better overall survival (OS, HR 0.42; CI 95%: 0.19-0.93; p = 0.032) and a trend towards better cancer-specific survival (CSS, HR 0.41 CI 95%: 0.17-1.03; p = 0.057) compared to patients without chemotherapy (HR 0.42; CI 95%: 0.19-0.93; p = 0.032). The difference in OS was still significant even after adjusting for sex, age, stage, differentiation, neoadjuvant chemotherapy and preoperative radiotherapy (HR 0.40; CI 95%: 0.17-0.92; p = 0.031). There was no such difference in the NMAC patients except in the stage-by-stage subgroup analyses where patients in stage IV had better survival after adjuvant chemotherapy.

CONCLUSIONS

There may be a difference in treatment response to adjuvant chemotherapy between MAC and NMAC patients. Patients with MAC could possibly benefit from adjuvant chemotherapy in stages II-IV. Further studies are however needed to confirm these results.

Global productivity and research trends of colorectal carcinoma: A scientometric analysis of studies published between 1980 and 2021

Although colorectal cancer (CRC) is a serious cause of death and has a significant impact on patients' quality of life and incidence rate of CRC has increased among the younger populations, bibliometric research of CRC has not been conducted yet. To perform a comprehensive analysis of scientific publications on CRC using various statistical and bibliometric techniques. Publications on CRC published between 1980 and 2021 were downloaded from the Web of Science database and analyzed using statistical methods. The trending topics, collaborations among countries, and citation relationships were analyzed using bibliometric network visualization mapping. The number of articles to be probably published in the next 5 years was estimated using the exponential smoothing estimator. The Spearman's correlation rank correlation coefficient was used to analyze the correlations among the variables. A total of 122,717 publications were found in the fields of oncology, gastroenterology, hepatology, and surgery. Of the published articles, 64,774 publications were research articles. The top five countries that contributed the most to the literature were the USA (16,604; 25.6%), China (10,567; 16.3%), Japan (7932; 12.2%), the UK (5009; 7.1%), and Italy (4287; 6.6%). The most prolific author, institution, and journal in the field of CRC were Zhang Y (n = 331), University of Texas System (n = 1646), and Diseases of the Colon and Rectum (n = 2090), respectively. The most influential journal based on the average number of citations received per article was CA-A Cancer Journal for Clinicians (citations per article; 286). There was a significant positive correlation between the number of articles produced by the countries on CRC and gross domestic product and human development index (r = 0.726, P < .001; r = 0.658, P < .001, respectively). Additionally, a significant moderate correlation of CRC was found with gross domestic product per capita (r = 0.711, P < .001). Keywords like overall survival, neoadjuvant chemoradiotherapy, locally advanced rectal cancer, robotic surgery, anastomotic leakage, chemoradiotherapy, metastatic colorectal cancer, KRAS, meta-analysis, colorectal surgery, and laparoscopic surgery were studied.

Transanal endoscopic microsurgery versus radical resection for early-stage rectal cancer: a systematic review and meta- analysis

PURPOSE

In the treatment of early-stage rectal cancer, a growing number of studies have shown that transanal endoscopic microsurgery is one of the alternatives to radical surgery adhering to total mesorectal excision that can reduce the incidence of adverse events without compromising treatment outcomes. The purpose of this meta-analysis is to compare the safety and treatment effect of transanal endoscopic microsurgery and radical surgery adhering to total mesorectal excision to provide a basis for clinical treatment selections.

METHOD

We searched the literatures of four major databases, PubMed, Embase, Web of science, and Cochrane Library, without limitation of time. The literatures included randomized controlled studies and cohort studies comparing two surgical procedures of transanal endoscopic microsurgery and radical surgery adhering to total mesorectal excision. Treatment effectiveness and safety results of transanal endoscopic microsurgery and radical surgery were extracted from the included literatures and statistically analyzed using RevMan5.4 and stata17.

RESULT

Ultimately, 13 papers were included in the study including 5 randomized controlled studies and 8 cohort studies. The results of the meta-analysis showed that the treatment effect and safety of both transanal endoscopic microsurgery and radical surgery in distant metastasis (RR, 0.59 (0.34, 1.02), P > 0.05), overall recurrence (RR, 1.49 (0.96, 2.31), P > 0.05), disease-specific-survival (RR, 0.74 (0.09, 1.57), P > 0.05), dehiscence of the sutureline or anastomosis leakage (RR, 0.57 (0.30, 1.06), P > 0.05), postoperative bleeding (RR, 0.47 (0.22, 0.99), P > 0.05), and pneumonia (RR, 0.37, (0.10, 1.40), P > 0.05) were not significantly different. However, they differ significantly in perioperative mortality (RR, 0.26 (0.07, 0.93, P < 0.05)), local recurrence (RR, 2.51 (1.53, 4.21), P < 0.05),_overall survival_ (RR, 0.88 (0.74, 1.00), P < 0.05), disease-free-survival (RR, 1.08 (0.97, 1.19), P < 0.05), temporary stoma (RR, 0.05 (0.01, 0.20), P < 0.05), permanent stoma (RR, 0.16 (0.08, 0.33), P < 0.05), postoperative complications (RR, 0.35 (0.21, 0.59), P < 0.05), rectal pain (RR, 1.47 (1.11, 1.95), P < 0.05), operation time (RR, -97.14 (-115.81, -78.47), P < 0.05), blood loss (RR, -315.52 (-472.47, -158.57), P < 0.05), and time of hospitalization (RR, -8.82 (-10.38, -7.26), P < 0.05).

CONCLUSION

Transanal endoscopic microsurgery seems to be one of the alternatives to radical surgery for early-stage rectal cancer, but more high-quality clinical studies are needed to provide a reliable basis.

Determinants of Pre-Surgical Treatment in Primary Rectal Cancer: A Population-Based Study

When preoperative radiotherapy (RT) is best used in rectal cancer is subject to discussions and guidelines differ. To understand the selection mechanisms, we analysed treatment decisions in all patients diagnosed between 2010-2020 in two Swedish regions (Uppsala with a RT department and Dalarna without). Information on staging and treatment (direct surgery, short-course RT, or combinations of RT/chemotherapy) in the Swedish Colorectal Cancer Registry were used. Staging magnetic resonance imaging (MRI) permitted a division into risk groups, according to national guidelines. Logistic regression explored associations between baseline characteristics and treatment, while Cohen's kappa tested congruence between clinical and pathologic stages. A total of 1150 patients without synchronous metastases were analysed. Patients from Dalarna were older, had less advanced tumours and were pre-treated less often (52% vs. 63%, p < 0.001). All MRI characteristics (T-/N-stage, MRF, EMVI) and tumour levels were important for treatment choice. Age affected if chemotherapy was added. The correlation between clinical and pathological T-stage was fair/moderate and poor for N-stage. The MRI-based risk grouping influenced treatment choice the most. Since the risk grouping was modified to diminish the pre-treated proportion, fewer patients were irradiated with time. MRI staging is far from optimal. A stronger wish to decrease irradiation may explain why fewer patients from Dalarna were irradiated, but inequality in health care cannot be ruled out.

Comparison of robotic versus laparoscopic lateral lymph node dissection for advanced lower rectal cancer: a retrospective study at two institutions

BACKGROUND

Lateral lymph node dissection (LLND) represents a technically challenging procedure. This study aimed to evaluate the perioperative, genitourinary functional and mid-term oncological outcomes of laparoscopic lateral lymph node dissection (LLLND) and robotic lateral lymph node dissection (RLLND) for advanced lower rectal cancer (ALRC).

METHODS

Between January 2015 and April 2021, consecutive patients who underwent RLLND and LLLND at two high-volume centres were enrolled. The perioperative outcomes, genitourinary function recovery and mid-term oncological outcomes of the patients were compared. A subgroup analysis of patients who underwent neoadjuvant chemoradiotherapy (nCRT) was performed.

RESULTS

A total of 205 patients were included in the analysis, with 95 in the RLLND group and 110 in the LLLND group. The patients in the RLLND group had a longer operative time, less blood loss, and more harvested internal iliac lymph nodes than did those in the LLLND group. In postoperative complication, urinary retention was less frequent in the RLLND group than in the LLLND group. Additionally, the RLLND group had better genitourinary function recovery. Similar results were also observed from the nCRT subgroup analysis. Moreover, there was no significant difference in mid-term oncological outcomes between the two groups. Further subgroup analysis indicated that the patients who underwent nCRT + LLLND/RLLND had better local control than those who underwent only LLLND/RLLND.

CONCLUSIONS

RLLND is safe and feasible for ALRC and is associated with more harvested internal iliac lymph nodes and better genitourinary function recovery. NCRT combined with minimally invasive LLND could constitute an improved strategy for ALRC.

The pattern of bowel dysfunction in patients with rectal cancer following the multimodal treatment: anorectal manometric measurements at before and after chemoradiation therapy, and postoperative 1 year

PURPOSE

Bowel dysfunction commonly occurs in patients with locally advanced rectal cancer treated with a multimodal approach of chemoradiation therapy (CRT) combined with sphincter-preserving rectal resection. This study investigated the decline in anorectal function using sequential anorectal manometric measurements obtained before and after the multimodal treatment as well as at a 1-year follow-up.

METHODS

This was a retrospective cohort study conducted in a single center. The study population consisted of patients with locally advanced mid- to low rectal cancer who received the preoperative CRT followed by sphincter-preserving surgery from 2012 to 2016. The anorectal manometric value measured after each treatment modality was compared to demonstrate the degree of decline in anorectal function. A generalized linear model of repeated measures was performed using the manometric values measured pre- and post-CRT, and at 12 months postoperatively.

RESULTS

Overall, 100 patients with 3 consecutive manometric data were included in the final analysis. In the overall cohort study, the mean resting and maximal squeezing pressures showed insignificant decrement post-neoadjuvant CRT. At a 1-year postoperative follow-up, the maximal squeezing pressure significantly decreased. The maximal rectal sensory threshold demonstrated significant reduction consecutively after each following treatment (P<0.001).

CONCLUSION

The short-term effect of neoadjuvant CRT on the anal sphincters was relatively trivial. The following sphincter-saving surgery resulted in a profound disruption of the anorectal function. Patients with rectal cancer should be consulted on the consequence of multimodal treatment.

Reappraisal of the Lymphatic Drainage System of the Distal Rectum: Functional Lymphatic Flow into the Presacral Space and Its Clinical Implication in Rectal Cancer Treatment

Understanding the source and route of pelvic metastasis is essential to developing an optimal strategy for controlling local and systemic diseases of rectal cancer. This study aims to delineate the distribution of lymphatic channels and flow from the distal rectum. In fresh-frozen cadaveric hemipelvis specimens, the ligamentous attachment of the distal rectum to the pelvic floor muscles and the presacral fascia were evaluated. Using indocyanine green (ICG) fluorescence imaging, we simultaneously evaluated the gross anatomy of the lymphatic communication of the distal rectum. We also investigated the lymphatic flow in the pelvic cavity intraoperatively in rectal cancer patients who underwent radical rectal resection with total mesorectal excision (TME). In fresh cadavers, multiple small perforating lymphovascular branches exist in the retrorectal space, posteriorly connecting the mesorectum to the presacral fascia. The lymphatic flow from the distal rectum drains directly into the presacral space through the branches. In patients who underwent TME for rectal cancer, intraoperative ICG fluorescence signals were seen in the pelvic sidewalls and the presacral space. This anatomical study demonstrated that the lymphatic flow from the distal rectum runs directly to the pelvic lateral sidewalls and the presacral space, suggesting a possible route of metastasis in distal rectal cancer.

Enhancement of radiation therapy by indoleamine 2,3 dioxygenase 1 inhibition through multimodal mechanisms

BACKGROUND

Indoleamine 2,3-dioxygenase 1 (IDO1) is an enzyme that converts tryptophan to kynurenine. IDO1 expression is found not only in tumor cells but also in immune cells and is associated with tumor proliferation and immune responses. IDO1 inhibitors and radiation may cooperatively suppress tumor proliferation through the alterations in the Wnt/β-catenin pathway, cell cycle, and immune response. We investigated the antitumor effects of combination therapy of an IDO1 inhibitor, 1-methyl tryptophan (1-MT), and radiation on colorectal cancer.

METHODS

In vitro experiments were conducted using human and murine colon cancer cell lines (HCT116, HT-29, and Colon26). Cell growth inhibition was assessed using a MTS assay and Clonogenic assay. Cells were cultured for 48 h with or without 500 µM 1-MT after exposure to radiation (4 Gy). Cell cycle effects and modulation of Wnt/β-catenin pathway were evaluated using western blot analysis, flow cytometry, RT-PCR. Subcutaneous Colon26 tumors in BALB/c mice were treated by oral 1-MT (6 mg/mL) for 2 weeks and/or local radiation (10 Gy/10 fr). Bromodeoxyuridine (BrdU) incorporation in tumor cells and expression of differentiation markers of immune cells were evaluated using immunohistochemistry.

RESULTS

1-MT and a small interfering RNA against IDO1 suppressed proliferation of all cell lines, which was rescued by kynurenine. Clonogenic assay showed that administration of 1-MT improved radiosensitivity by suppressing the Wnt/β-catenin pathway activated by radiation and enhancing cell cycle arrest induced by radiation. Combination therapy showed a further reduction in tumor burden compared with monotherapies or untreated control, inducing the highest numbers of intratumoral CD3 + and CD8 + T cells and the lowest numbers of Foxp3 + and BrdU-positive tumor cells.

CONCLUSIONS

The combination of 1-MT and radiation suppressed colon cancer cells in vitro and in vivo via multiple mechanisms.