Long-term oncologic outcome following preoperative combined modality therapy and total mesorectal excision of locally advanced rectal cancer

Rectal Cancer Survival for Residual Carcinoma In Situ Versus Pathologic Complete Response After Neoadjuvant Therapy

BACKGROUND

Pathologic complete response after neoadjuvant chemoradiotherapy for rectal cancer is associated with improved survival. It is unclear whether residual carcinoma in situ portends a similar outcome.

OBJECTIVE

To compare the survival of patients with locally advanced rectal cancer who received neoadjuvant therapy and achieved pathologic carcinoma in situ versus pathologic complete response.

DESIGN

Retrospective cohort study.

SETTING

National public database.

PATIENTS

A total of 4594 patients in the National Cancer Database from 2006 to 2016 with locally advanced rectal cancer who received neoadjuvant therapy, underwent surgery, and had node-negative ypTis or ypT0 on final pathology were included. Of these, 4321 patients (94.1%) had ypT0 and 273 (5.9%) had ypTis on final pathology.

MAIN OUTCOME MEASURE

Overall survival.

RESULTS

The median age was 60 years, and 1822 patients (39.7%) were women. On initial staging, 54.5% (n = 2503) had stage II disease and 45.5% (n = 2091) had stage III disease. The ypTis group had decreased overall survival compared to the ypT0 group (HR 1.42; 95% CI, 1.04-1.95; p  = 0.028). Other factors associated with decreased overall survival were older age at diagnosis, increasing Charlson-Deyo score, and poorly differentiated tumor grade. Variables associated with improved survival were female sex, private insurance, and receipt of both neoadjuvant and adjuvant chemotherapy. For the total cohort, there was no difference in survival between clinical stage II and stage III.

LIMITATIONS

Standard therapy versus total neoadjuvant therapy could not be abstracted. Overall survival was defined as the time from surgery to death from any cause or last contact, allowing for some erroneously misclassified deaths.

CONCLUSIONS

ypTis is associated with worse overall survival than ypT0 for patients with locally advanced rectal cancer who receive neoadjuvant chemoradiotherapy followed by surgery. For this cohort, clinical stage was not a significant predictor of survival. Prospective trials comparing survival for these pathologic outcomes are needed. See Video Abstract .

SUPERVIVENCIA DEL CNCER DE RECTO PARA EL CARCINOMA RESIDUAL IN SITU VS RESPUESTA PATOLGICA COMPLETA DESPUS DE LA TERAPIA NEOADYUVANTE

ANTECEDENTESLa respuesta patológica completa después de la quimiorradioterapia neoadyuvante para el cáncer de recto se asocia con una mayor supervivencia. No está claro si el carcinoma residual in situ presagia un resultado similar.OBJETIVOComparar la supervivencia de pacientes con cáncer de recto localmente avanzado que recibieron terapia neoadyuvante y lograron un carcinoma patológico in situ versus una respuesta patológica completa.DISEÑOEstudio de cohorte retrospectivo.ESCENARIOBase de datos pública nacional.PACIENTESSe incluyeron 4,594 pacientes de la Base de Datos Nacional de Cáncer de 2006 a 2016 con cáncer de recto localmente avanzado que recibieron terapia neoadyuvante, fueron sometidos a cirugía y tuvieron ganglios negativos, ypTis o ypT0 en el reporte patológico final. 4.321 (94,1%) tuvieron ypT0 y 273 (5,9%) tuvieron ypTis en el reporte final.PRINCIPALES MEDIDAS DE RESULTADOSupervivencia general.RESULTADOSLa mediana de edad fue de 60 años. 1.822 pacientes (39,7%) fueron mujeres. El 54,5% (n = 2.503) tuvo la enfermedad en estadio II y el 45,5% (n = 2.091) tuvo la enfermedad en estadio III según la estadificación inicial. El grupo ypTis tuvo una supervivencia general reducida en comparación con el grupo ypT0 (HR 1,42, IC 95 % 1,04-1,95, p = 0,028). Otros factores asociados con una menor supervivencia general fueron una edad más avanzada al momento del diagnóstico, un aumento de la puntuación de Charlson-Deyo y un grado tumoral poco diferenciado. Las variables asociadas con una mejor supervivencia fueron el sexo femenino, el seguro privado y la recepción de quimioterapia neoadyuvante y adyuvante. Para la cohorte total, no hubo diferencias en la supervivencia entre el estadio clínico 2 y el estadio 3.LIMITACIONESNo se pudo resumir el tratamiento estándar versus el tratamiento neoadyuvante total. La supervivencia general se definió como el tiempo transcurrido desde la cirugía hasta la muerte por cualquier causa o último contacto, lo que permite algunas muertes erróneamente clasificadas.CONCLUSIONESypTis se asocia con una peor supervivencia general que ypT0 en pacientes con cáncer de recto localmente avanzado que reciben quimiorradioterapia neoadyuvante seguida de cirugía. Para esta cohorte, el estadio clínico no fue un predictor significativo de supervivencia. Se necesitan ensayos prospectivos que comparen la supervivencia de estos resultados patológicos. ( Traducción-Dr Osvaldo Gauto ).

Predictive Value of Tumor-Infiltrating Lymphocytes and Ki-67 for Pathological Response to Total Neoadjuvant Therapy in Rectal Cancer

PURPOSE

Patients with locally advanced rectal cancer (LARC) who underwent total neoadjuvant therapy (TNT) showed an increase in the percentage of complete pathological response (pCR). The purpose of this study was to determine the correlation between Ki-67, tumor-infiltrating lymphocytes (TIL), and TNT in LARC patients.

METHOD

In total, one hundred fifty-nine patients with LARC were included in this prospective study. The international working group was used to categorize the TIL into three groups based on the percentage and density of staining: group 0 (0-10%), group 1 (11-59%), and group 2 (≥ 60%). Ki-67 expression was classified as low (≤ 50%) or high (> 50%).

RESULT

Most patients had tumor grade III (74.2%) and T2-T3 (78.6%). Lymph node involvement (48.7%) and tumor size ≥ 3 cm were detected in approximately half of the patients. Forty-four percent of patients had a high Ki-67 index; 15.7% of patients belonged to group 1, and 21.4% belonged to group 2. pCR was detected in 18.2% of the patients. TIL and Ki-67 levels were significantly correlated with pCR (p = 0.001 and 0.003 for multivariate analysis and 0.001 and 0.03 for univariate analysis, respectively).

CONCLUSION

There was a statistically significant correlation between Ki-67, TIL, and pCR following TNT protocol, which may help maximize the therapeutic outcome.

Recurrence of rectal cancer on the pelvic sidewall after lateral lymph node dissection

PURPOSE

Although lateral lymph node dissection has been performed to prevent lateral pelvic recurrence in locally advanced lower rectal cancer, the incidence of lateral pelvic recurrence after this procedure has not been investigated. Therefore, this study aimed to investigate the long-term outcomes of patients who underwent lateral pelvic lymph node dissection, with a particular focus on recurrence patterns.

METHODS

This was a retrospective study conducted at a single high-volume cancer center in Japan. A total of 493 consecutive patients with stage II-III rectal cancer who underwent lateral lymph node dissection between January 2005 and August 2022 were included. The primary outcome measures included patterns of recurrence, overall survival, and relapse-free survival. Patterns of recurrence were categorized as lateral or central pelvic.

RESULTS

Among patients who underwent lateral lymph node dissection, 18.1% had pathologically positive lateral lymph node metastasis. Lateral pelvic recurrence occurred in 5.5% of patients after surgery. Multivariate analysis identified age > 75 years, lateral lymph node metastasis, and adjuvant chemotherapy as independent risk factors for lateral pelvic recurrence. Evaluation of the recurrence rate by dissection area revealed approximately 1% of recurrences in each area after dissection.

CONCLUSION

We demonstrated the prognostic outcome and limitations of lateral lymph node dissection for patients with advanced lower rectal cancer, focusing on the incidence of recurrence in the lateral area after the dissection. Our study emphasizes the clinical importance of lateral lymph node dissection, which is an essential technique that surgeons should acquire.

Does neoadjuvant rectal score predict treatment outcomes better than the all grading systems used in neoadjuvantly treated rectal cancer?

BACKGROUND

/Objective: To compare the prognostic value of the yield pathologic (yp) stage, used 4 tumor regression grading (TRG) systems, and neoadjuvant rectal score(NARS) in patients with locally advanced rectal cancer (LARC) who received long-term neoadjuvant chemoradiotherapy (nCRT).

METHODS

Between 2005 and 2017, we included 302 patients with LARC who treated with nCRT. Postoperative pathological responses were graded by using Dworak, American Joint Committee on Cancer, Mandart, Memorial Sloan Kettering Cancer Center, grading systems and NARS([5ypN-3(kT-pT)+12]2/9,61) calculations. Their results were compared in terms of treatment outcomes.

RESULTS

The median follow-up time was 51 months (range 5-136). There was a significant relation between cT stage and the response in used grading systems(p < 0,001). Median overall(OS), local recurrence free(LRFS), and distant metastasis free(MFS) survival rates were 50, 48, and 45 months, respectively. 5-year OS, LRFS, and MFS rates were 71%, 92%, and 72%, respectively. According to the NARS and treatment response grating systems, a significant difference was found between the low risk and high risk groups in terms of OS, LRFS, and MFS rates. While it was not seen any difference in terms of OS and MFS, NARS was found to predict LRFS better than other grading systems. In multivariate analysis, high NARS was found to be correlated with worse OS and worse MFS. On the other hand, pCR was the another important factor affecting treatment outcomes.

CONCLUSIONS

While used systems except NARS group patients according to ypT status in surgical tissue, NARS add the value of ypN status in addition to ypT status. It could be suggested to use NARS to predict LRFS.

SUMO-Activating Enzyme Subunit 1 Is Associated with Poor Prognosis, Tumor Progression, and Radio-Resistance in Colorectal Cancer

Concurrent chemoradiotherapy is an effective treatment option for patients with low-grade colorectal cancer (CRC) in the local disease stage. At present, the principle of the Taiwan Medical Center is to treat CRC patients with combination radiotherapy and chemotherapy (high-dose 5-FU) for a period of about five weeks prior to surgery. Radical resection of the tumor is performed at least six to eight weeks after concurrent chemoradiotherapy (CCRT). However, this approach fails to produce the desired therapeutic effect in approximately 20% to 30% of patients, and such patients are unnecessarily exposed to the risks of radiation and drug toxicity posed by this therapy. Therefore, it is crucial to explore new biomarkers to predict the prognosis of CRC. SUMO-activating enzyme subunit 1 (SAE1) plays an important role in SUMOylation, a post-translational modification involved in cellular functions, such as cell proliferation, cell cycle, and apoptosis. In our study, to explore the clinical-pathological role of SAE1 protein in CRC, we evaluated the clinical data and paraffin sections from CRC patients. The expression of SAE1 was evaluated using immunohistochemical analysis, and clinical parameters were analyzed using chi-square and Kaplan-Meier survival tests. The results of in vitro proliferation and radiosensitive assays were compared between control groups and SAE1 siRNA groups. Western blotting was also used to detect the expressions of the SAE1, PARP, cyclin D1, p-NF-κB, and NF-κB proteins. Flow cytometry and colony formation assays were used to detect the effect of SAE-1 on radiosensitivity. In vivo, we detected the growth curve in a mouse xenograft model. The results showed that SAE-1 was revealed to be an independent prognostic biomarker of CRC. SAE1 knockdown inhibited CRC proliferation in vitro and in vivo, and led to the cleavage of PARP, downregulation of cyclin D1 protein expression, and downregulation of p-NF-κB/NF-κB. Additionally, SAE1 knockdown promoted radiosensitivity in CRC cells. Therefore, it was inferred that SAE1 may be used as a potential therapeutic target in CRC treatment.

Time Interval Between the End of Neoadjuvant Therapy and Elective Resection of Locally Advanced Rectal Cancer in the CRONOS Study

Importance

The treatment for extraperitoneal locally advanced rectal cancer (LARC) is neoadjuvant therapy (NAT) followed by total mesorectal excision (TME). Robust evidence on the optimal time interval between NAT completion and surgery is lacking.

Objective

To assess the association of time interval between NAT completion and TME with short- and long-term outcomes. It was hypothesized that longer intervals increase the pathologic complete response (pCR) rate without increasing perioperative morbidity.

Design, Setting, and Participants

This cohort study included patients with LARC from 6 referral centers who completed NAT and underwent TME between January 2005 and December 2020. The cohort was divided into 3 groups depending on the time interval between NAT completion and surgery: short (≤8 weeks), intermediate (>8 and ≤12 weeks), and long (>12 weeks). The median follow-up duration was 33 months. Data analyses were conducted from May 1, 2021, to May 31, 2022. The inverse probability of treatment weighting method was used to homogenize the analysis groups.

Exposure

Long-course chemoradiotherapy or short-course radiotherapy with delayed surgery.

Main outcome and Measures

The primary outcome was pCR. Other histopathologic results, perioperative events, and survival outcomes constituted the secondary outcomes.

Results

Among the 1506 patients, 908 were male (60.3%), and the median (IQR) age was 68.8 (59.4-76.5) years. The short-, intermediate-, and long-interval groups included 511 patients (33.9%), 797 patients (52.9%), and 198 patients (13.1%), respectively. The overall pCR was 17.2% (259 of 1506 patients; 95% CI, 15.4%-19.2%). When compared with the intermediate-interval group, no association was observed between time intervals and pCR in short-interval (odds ratio [OR], 0.74; 95% CI, 0.55-1.01) and long-interval (OR, 1.07; 95% CI, 0.73-1.61) groups. The long-interval group was significantly associated with lower risk of bad response (tumor regression grade [TRG] 2-3; OR, 0.47; 95% CI, 0.24-0.91), systemic recurrence (hazard ratio, 0.59; 95% CI, 0.36-0.96), higher conversion risk (OR, 3.14; 95% CI, 1.62-6.07), minor postoperative complications (OR, 1.43; 95% CI, 1.04-1.97), and incomplete mesorectum (OR, 1.89; 95% CI, 1.02-3.50) when compared with the intermediate-interval group.

Conclusions and Relevance

Time intervals longer than 12 weeks were associated with improved TRG and systemic recurrence but may increase surgical complexity and minor morbidity.

An attention-based neural network model for automatic partition of abdominal lymph nodes in CT imaging

Background

Abdominal lymph node partition is highly relevant to colorectal cancer (CRC) metastasis, which may further affect patient prognosis and survival quality. In the traditional diagnostic process, medical radiologists must partition all lymph nodes from the computed tomography (CT) images for further diagnostics. The manual interpretation of abdominal nodes is experience-dependent and time-consuming, especially for node partition. Therefore, automated partition methods are desirable to make the diagnostic process more accessible. Automatic abdominal lymph node partition is a challenging task due to the subtle morphological features of the nodes and the complex relative position information of the abdominal structure.

Methods

In this paper, a node-oriented dataset containing 6,880 nodes with partition labels was constructed by seasoned professionals through 2-round annotation due to there being no dataset with node-oriented labels to perform the partition task. In addition, specific masking strategies and attention mechanisms were proposed for the primary deep neural networks (DNNs). The specific masking strategy could utilize the positional and morphological information more substantially, which intensively exploits prior knowledge and hones the relative positional information in the lower abdomen. The comprehensive attention mechanism could introduce direction-aware information to enhance the inter-channel relationship of features and capture rich contextual relationships with multi-scale kernels.

Results

The experiments were based on the node-oriented dataset. The proposed method achieved superior performance [accuracy (ACC): 89.74%; F1 score (F1): 85.95%; area under the curve (AUC): 88.23%], which is significantly higher than the baseline model with several masking strategies (ACC: 62.05-86.16%; F1: 51.77-80.86%; AUC: 60.44-83.94%). For exploration of attention, the proposed method also outperformed the state-of-the-art convolutional block attention module (CBAM; ACC: 88.90%; F1: 84.09%; AUC: 86.86%) with the same proposed input form.

Conclusions

Experimental results indicate that the innovative method performs better in experimental metrics than other prevalent methods. The proposed method is expected to be introduced in future medical scenarios, which will help doctors to optimize the diagnosis workflow and improve partition sensitivity.

Total neoadjuvant therapy for rectal cancer: evidence and challenge

Recent advances in the management of rectal cancer have dramatically changed the clinical practice of colorectal surgeons because the main focus of rectal cancer treatment has changed from sphincter-saving to an organ-preserving strategies. Modifying the delivery of systemic chemotherapy to improve patients' survival is another progress in colorectal cancer management, known as total neoadjuvant therapy (TNT). TNT is a new strategy used by colorectal surgeons to improve the quality of life and survival of patients after treatment. TNT poses limitations or obstacles, such as overtreatment issues in patients with stage I rectal cancer. However, considering the quality-of-life issues in patients with low-lying rectal cancer necessitating a permanent colostomy, the indication for TNT will be expanded. This review summarizes the recently conducted clinical trials and foresees future perspectives on TNT.

Early Age of Onset Is an Independent Predictor for a Worse Response to Neoadjuvant Therapies in Sporadic Rectal Cancer Patients

The incidence of rectal cancer (RC) is increasing in the population aged ≤ 49 (early-onset RC-EORC). EORC patients are more likely to present with locally advanced disease at diagnosis than late-onset RC (LORC; aged ≥ 50) patients. As a consequence, more EORC patients undergo neoadjuvant therapies. The response to treatment in EORC patients is still unknown. This study aims to explore the effect of age of onset on the pathological response to neoadjuvant therapies in sporadic locally advanced RC (LARC) patients. Based on an institutional prospectively maintained database, LARC patients undergoing neoadjuvant therapies and radical surgery between January 2010 and December 2022 were allocated to the EORC and LORC groups. The primary endpoint was the rate of incomplete response (Dworak 0-2). A total of 326 LORC and 79 EORC patients were included. Pre-neoadjuvant tumor features were comparable. A significantly higher rate of incomplete response was observed in EORC patients (49% vs. 35%; p = 0.028). From multivariable analysis, early age of onset, smoking and extramural invasion presented as independent risk factors for a worse response. This study demonstrates that an early age of onset is related to a worse response and calls for different multimodal strategies in this group of patients.

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.

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.

Clinical Implication of Perineural and Lymphovascular Invasion in Rectal Cancer Patients Who Underwent Surgery After Preoperative Chemoradiotherapy

BACKGROUND

Lymphovascular and perineural invasion are well-known negative prognostic indicators in rectal cancer, but previous studies on their significance are not consistent.

OBJECTIVE

This study assessed the prognostic value of lymphovascular and perineural invasion in rectal cancer patients who received preoperative chemoradiotherapy followed by curative resection.

DESIGN

This is a retrospective analysis.

SETTING

This study was performed at a tertiary cancer center.

PATIENTS

Rectal cancer patients who underwent curative resection after preoperative chemoradiotherapy between January 2000 and December 2010.

MAIN OUTCOME MEASURES

The primary outcomes were disease-free survival and overall survival. The survival rates were estimated using Kaplan-Meier analysis, and group comparisons were conducted using a log-rank test.

RESULTS

Of the 1156 included patients, 109 (9.4%) presented with lymphovascular invasion and 137 (11.9%) presented with perineural invasion. Lymphovascular and perineural invasion were associated with T and N downstaging after preoperative chemoradiotherapy ( p < 0.001). In the ypN0 patients, the 5-year disease-free survival rates were 70.8% and 78.5% ( p = 0.150) for the lymphovascular invasion and absent groups, respectively. In the perineural invasion group, the 5-year disease-free survival rate was 59.0% compared to 80.2% in the absent group ( p = 0.001). Among the ypN+ patients, the 5-year disease-free survival rates were 36.9% and 44.4% for the lymphovascular invasion and absent groups, respectively ( p = 0.211). The perineural invasion group had a poorer 5-year disease-free survival rate compared to the absent group (29.7% vs 46.7%; p = 0.011). By multivariable analyses, perineural invasion correlated with a poor disease-free survival (HR 1.412, 95% CI 1.082-1.843; p = 0.011) and also in ypN0 subgroup analysis (HR 1.717, 95% CI 1.093-2.697; p = 0.019).

LIMITATIONS

This study was a retrospective study conducted at a single center.

CONCLUSIONS

Perineural invasion is a reliable independent predictor of recurrence in rectal cancer patients treated with preoperative chemoradiotherapy. Patients with perineural invasion should be considered for closer surveillance even with ypN0 status. See Video Abstract at http://links.lww.com/DCR/B833 .IMPLICACIÓN CLÍNICA DE LA INVASIÓN PERINEURAL Y LINFOVASCULAR EN PACIENTES CON CÁNCER DE RECTO SOMETIDOS A CIRUGÍA DESPUÉS DE QUIMIORRADIOTERAPIA PREOPERATORIA.

ANTECEDENTES

La invasión linfovascular y perineural en cancer de recto, son indicadores pronósticos negativos bien conocidos, pero estudios previos sobre su significancia, no son consistentes.

OBJETIVO

El estudio evaluó el valor pronóstico de la invasión linfovascular y perineural en pacientes con cáncer de recto sometidos a quimiorradioterapia preoperatoria seguida de resección curativa.

DISEO

Es un análisis retrospectivo.

ENTORNO CLINICO

El estudio se realizó en un centro oncológico terciario.

PACIENTES

Pacientes con cáncer de recto sometidos a resección curativa después de quimiorradioterapia preoperatoria entre enero de 2000 y diciembre de 2010.

PRINCIPALES MEDIDAS DE VALORACION

Los resultados primarios fueron la supervivencia libre de enfermedad y la supervivencia general. Las tasas de supervivencia se estimaron mediante el análisis de Kaplan-Meier y las comparaciones de grupos se realizaron mediante una prueba de rango logarítmico.

RESULTADOS

De los 1156 pacientes incluidos, 109 (9,4%) presentaron invasión linfovascular y 137 (11,9%) invasión perineural. La invasión linfovascular y perineural se asoció con reducción del estadio de T y N después de la quimiorradioterapia preoperatoria ( p < 0,001). En los pacientes ypN0, las tasas de supervivencia libre de enfermedad a 5 años fueron del 70,8% y el 78,5% ( p = 0,150) para los grupos con y sin invasión linfovascular, respectivamente. En el grupo de invasión perineural, la tasa de supervivencia libre de enfermedad a 5 años fue del 59,0%, en comparación con el 80,2% en el grupo ausente ( p = 0,001). Entre los pacientes ypN +, las tasas de supervivencia sin enfermedad a 5 años fueron del 36,9% y 44,4% para los grupos con y sin invasión linfovascular, respectivamente ( p = 0,211). El grupo de invasión perineural mostró una tasa de supervivencia libre de enfermedad a 5 años menor, en comparación con el grupo ausente (29,7% versus 46,7%, p = 0,011). Mediante análisis multivariable, la invasión perineural se correlacionó con una pobre tasa de supervivencia de enfermedad (índice de riesgo 1,412; intervalo de confianza del 95%: 1,082-1,843; p = 0,011) y también en el análisis de subgrupos ypN0 (índice de riesgo 1,717; intervalo de confianza del 95%: 1,093-2,697; p = 0,019).

LIMITACIONES

Estudio retrospectivo realizado en un solo centro.

CONCLUSIONES

La invasión perineural es un predictor independiente y confiable de recurrencia en pacientes con cáncer de recto tratados con quimiorradioterapia preoperatoria. Los pacientes con invasión perineural deben considerarse para una vigilancia más estrecha incluso con estadio ypN0. Consulte Video Resumen en http://links.lww.com/DCR/B833 . (Traducción-Dr. Fidel Ruiz Healy ).

Pathologic Implications of Radial Resection Margin and Perineural Invasion to Adjuvant Chemotherapy after Preoperative Chemoradiotherapy and Surgery for Rectal Cancer: A Multi-Institutional and Case-Matched Control Study

We assessed the exact role of adjuvant chemotherapy after neoadjuvant chemoradiotherapy (CRT) and surgery in rectal cancer patients with positive surgical margin or perineural invasion (PNI). This multi-institutional study included 1799 patients with rectal cancer at cT3-4N0-2M0 stages. Patients were divided into two groups. The high-risk group had a positive margin and/or perineural invasion. The low-risk group showed no positive margin or PNI. Propensity-score matching analysis was performed, and a total of 928 patients, with 464 in each arm, were evaluated. The high-risk group showed significant differences in overall survival (OS, 73.4% vs. 53.9%, p < 0.01) and recurrence-free survival (RFS, 52.7% vs. 40.9%, p = 0.01) at five years between the adjuvant chemotherapy arm and observation arm. The low-risk group showed no significant differences in 5-year OS (p = 0.61) and RFS (p = 0.75) between the two arms. Multivariate analyses showed that age, pathologic N stage, and adjuvant chemotherapy were significantly correlated with OS and RFS in the high-risk group (all p < 0.05). Adjuvant chemotherapy improved OS and RFS more significantly in rectal cancer patients with positive surgical margin or PNI than in those with negative surgical margin and PNI.

High Neutrophil-Lymphocyte Ratio, Platelet-Lymphocyte Ratio and Low Lymphocyte Levels Are Correlated With Worse Pathological Complete Response Rates

OBJECTIVE

To investigate the effect of hemogram parameters on predicting pathological complete response (pCR) in locally advanced rectal cancer.

METHODOLOGY

A total of 227 patients with rectal cancer treated with neoadjuvant concurrent chemoradiotherapy (CRT) were retrospectively analyzed. All patients were divided into two subgroups as high or low hemogram parameters according to the cut-off value obtained using the receiver operating characteristic (ROC) curve.

RESULTS

In patients with low neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) levels, pCR rate was statistically significantly higher than the group with high NLR and PLR levels (for NLR: 39.77% vs. 5.34%; p<0.001, for PLR: 32.38% vs 7.01%; p<0.001 respectively). In addition, the pCR rate was significantly better in patients with high lymphocyte levels compared to the group with low lymphocyte levels (33.33% vs. 7.5%; p<0.001, respectively). According to the multivariate logistic regression analysis result, NLR and PLR levels were considered as independent predictors to predict pathological complete response [p<0.001, HR: 0.128 (95% CI=0.051 - 0.322) for NLR; p=0.017, HR: 0.332 (95% CI=0.134 - 0.821) for PLR, respectively].

CONCLUSION

Our study showed that high NLR, PLR, and low lymphocyte levels were correlated with worse pCR rates. In addition to that, NLR and PLR emerged as independent predictive markers.

Expression of non-homologous end joining factor, Ku80, is negatively correlated with PD-L1 expression in cancer cells after X-ray irradiation

The growing importance of antitumour immunity by cancer immunotherapy has prompted studies on radiotherapy-induced immune response. Previous studies have indicated that programmed cell death-1 ligand (PD-L1) expression is regulated by DNA damage signalling. However, PD-L1 up-regulation after radiotherapy has not been fully investigated at the clinical level, particularly in the context of expression of DNA repair factors. The present study examined the correlation of mRNA expression between PD-L1 and non-homologous end joining (NHEJ) factors using The Cancer Genome Atlas database analysis. Among NHEJ factors, Ku80 mRNA expression was negatively correlated with PD-L1 mRNA expression levels in several types of cancer (colon adenocarcinoma, breast invasive carcinoma, skin cutaneous melanoma, lung adenocarcinoma, head and neck squamous cell carcinoma, uterine corpus endometrial carcinoma, cervical squamous cell carcinoma and endocervical adenocarcinoma). To verify the negative correlation in clinical samples, the present study analysed whether Ku80 expression levels affected PD-L1 up-regulation after radiotherapy using cervical squamous cell carcinoma samples. Quantitative evaluation using software analysis of immunohistochemically stained slides revealed that patients with low Ku80 positivity in biopsy specimens demonstrated increased PD-L1 expression levels after 10 Gy irradiation (Spearman's rank correlation coefficient=−0.274; P=0.017). Furthermore, PD-L1 induction levels in tumour cells after 10 Gy of irradiation were significantly inversely correlated with Ku80 expression levels (Spearman's rank correlation coefficient=−0.379; P<0.001). The present study also confirmed that short interfering RNA-mediated Ku80 depletion was associated with greater X-ray-induced PD-L1 up-regulation in HeLa cells. These results indicated that radiotherapy could enhance PD-L1 induction in tumour cells with low Ku80 expression in a clinical setting. Furthermore, these data highlighted Ku80 as a potential predictive biomarker for immune checkpoint therapy combined with radiotherapy.

SDF-1 expression after preoperative chemoradiotherapy is associated with prognosis in patients with advanced lower rectal cancer

Stromal cell-derived factor-1 (SDF-1) expression is associated with cancer progression, as a biomarker of prognosis. We clarified the significance of SDF-1 expression on chemoradiotherapy (CRT) resistance and prognosis in advanced lower rectal cancer patients. We evaluated 98 patients with advanced lower rectal cancer who underwent preoperative CRT. All patients received 40 Gy of radiation therapy, with concurrent chemotherapy containing fluorinated pyrimidines, followed by surgical resection. SDF-1 expression in surgical specimens was examined by immunohistochemistry. We divided the patients into SDF-1-positive- (n = 52) and SDF-1-negative groups (n = 46) and compared the clinicopathological factors and survival rates. The SDF-1-positive group was more resistant to CRT than the SDF-1-negative group (non-responder rate, 63.5% vs. 47.8%, respectively ; p = 0.12). Overall survival (OS) in the SDF-1 positive group was significantly poorer vs. the SDF-1-negative group (5-year OS, 73.4% vs. 88.0%, respectively ; p = 0.02), and disease-free survival (DFS) was worse (5-year DFS, 61.0% vs. 74.1%, respectively ; p = 0.07). Multivariate analysis confirmed that SDF-1 expression was a significant independent prognostic predictor of OS (p = 0.04). SDF-1 expression after preoperative CRT is significantly associated with a poor prognosis in advanced lower rectal cancer patients and is a promising biomarker. J. Med. Invest. 68 : 309-314, August, 2021.

Treatment in locally advanced rectal cancer: a machine learning bibliometric analysis

A bibliometric analysis was performed using a machine learning bibliometric methodology in order to evaluate the research trends in locally advanced rectal cancer treatment between 2000 and 2020. Information regarding publication outputs, countries, institutions, journals, keywords, funding, and citation counts was retrieved from Scopus database. During the search process, a total of 2370 publications were identified. The vast majority of papers originated from the United States of America, reflecting also its research drive in the collaboration network. Neoadjuvant treatment was the topic most studied in the highly cited studies. New keywords, including neoadjuvant chemotherapy, multiparametric magnetic resonance imaging, circulating tumor DNA, and genetic heterogeneity, appeared in the last 2 years. The quantity of publications on locally advanced rectal cancer treatment since 2000 showed an evolving research field. The 'new' keywords explain where research is presently heading.

Impact of dose-escalated chemoradiation on quality of life in patients with locally advanced rectal cancer: two year follow-up of the randomized RECTAL-BOOST trial

BACKGROUND

Dose-escalated chemoradiation (CRT) for locally advanced rectal cancer (LARC) did not result in higher complete response rates, but initiated more tumor regression in the randomized XXXXX trial (Clinicaltrials.gov XXXXX). This study compared patient reported outcomes (PROs) between patients who received dose-escalated CRT (5 × 3Gy boost + CRT) or standard CRT for two years following randomization.

METHODS

Patients with LARC, participating in the XXXXX trial, filled out EORTC QLQ-C30 and CR29 questionnaires on quality of life (QoL) and symptoms at baseline, 3, 6, 12, 18 and 24 months following start of treatment. Between-group differences in functional QoL domains were estimated using a linear mixed-effects model and expressed as effect size (ES). Symptom scores were compared using Mann-Whitney U test.

RESULTS

Patients treated with dose-escalated CRT (boost group, n=51) experienced a significantly stronger decline in global health at 3 and 6 months (ES -0,4 and ES -0,4), physical functioning at 6 months (ES -1,1), role functioning at 3 and 6 months (ES -0,8 and ES -0,6) and social functioning at 6 months (ES -0,6) compared to patients treated with standard CRT (control group, n=64). The boost group reported significantly more fatigue at 3 and 6 months (83% vs. 66% resp. 89% vs. 76%), pain at 3 and 6 months (67% vs. 36% resp. 80% vs. 44%) and diarrhea at 3 months (45% vs. 29%) compared to the control group. From 12 months onwards, QoL and symptoms were similar between groups, apart from more blood/mucus in stool in the boost group.

CONCLUSION

In patients with LARC, dose-escalated CRT resulted in a transient deterioration in global health, physical, role, and social functioning and more pain, fatigue and diarrhea at 3 and 6 months following start of treatment compared to standard CRT. From 12 months onwards, the impact of dose-escalated CRT on QoL largely resolved.

CTSE Overexpression Is an Adverse Prognostic Factor for Survival among Rectal Cancer Patients Receiving CCRT

The introduction of preoperative concurrent chemoradiotherapy (CCRT) increases the rate of anal preservation and allows tumor downstaging for clinical stage T3/T4 or node-positive rectal cancer patients. However, there is no precise predictive tool to verify the presence of residual tumor apart from surgical resection. The gastrointestinal (GI) tract not only digests nutrients but also coordinates immune responses. As the outermost layer of the GI tract, mucus plays a key role in mediating the interaction between the digestive and immune systems, and aberrant mucus mesh formation may cause chemoresistance by impeding drug delivery. However, the correlations among digestion-related genes, mucin synthesis, and chemoresistance remain poorly understood. In the present study, we evaluated genes related to digestion (GO: 0007586) and identified cathepsin E (CTSE), which is involved in immune regulation, as the most significantly upregulated gene associated with CCRT resistance in rectal cancer in a public transcriptome dataset (GSE35452). We recovered 172 records of rectal cancer patients receiving CCRT followed by surgical resection from our biobank and evaluated the expression level of CTSE using immunohistochemistry. The results revealed that tumors with CTSE overexpression were significantly correlated with pre-CCRT and post-CCRT positive nodal status (both p < 0.001), advanced pre-CCRT and post-CCRT tumor status (p < 0.001 and p = 0.002), perineural invasion (p = 0.023), vascular invasion (p < 0.001), and a lesser degree of tumor regression (p = 0.003). At the univariate level, CTSE overexpression was an adverse prognostic factor for all three endpoints: disease-specific survival (DSS), metastasis-free survival (MeFS) (both p < 0.0001), and local recurrence-free survival (LRFS) (p = 0.0001). At the multivariate level, CTSE overexpression remained an independent prognostic factor for poor DSS, MeFS (both p = 0.005), and LRFS (p = 0.019). Through bioinformatics analysis, we speculated that CTSE overexpression may confer CCRT resistance by forming a defensive mucous barrier. Taken together, these results suggest that CTSE overexpression is related to CCRT resistance and inferior survival in rectal cancer patients, highlighting the potential predictive and prognostic value of CTSE expression.

Prognostic Impact of the Neoadjuvant Rectal Score as Compared With the Tumor Regression Grade and Yield Pathologic TNM Stage in Patients With Locally Advanced Rectal Cancer After Neoadjuvant Chemoradiotherapy

BACKGROUND/AIM

The present study compared the prognostic value of the yield pathologic (yp) stage, tumor regression grade (TRG), and neoadjuvant rectal (NAR) score in patients with locally advanced rectal cancer (LARC) who received neoadjuvant chemoradiotherapy (nCRT).

PATIENTS AND METHODS

For the assessment of tumor regression, the Dworak grading system was used. The NAR score was calculated using the following equation: (5ypN-3[cT-ypT]+12)²÷9.61.

RESULTS

In univariate analysis, the NAR score and ypTNM stage were significantly associated with DFS [hazard ratio (HR)=2.514, p<0.001 and HR=3.200, p<0.001] and OS (HR=2.292, p=0.001 and HR=2.859, p<0.001), whereas the TRG was significantly associated with only DFS (HR=2.008, p=0.017). In multivariate analysis, the ypTNM stage was the only independent prognostic factor for DFS (HR=3.796, p<0.001) and OS (HR=3.591, p=0.0034).

CONCLUSION

Only the ypTNM stage was significantly associated with survival outcomes in multivariate analysis, suggesting that it is the most powerful prognostic factor of nCRT in patients with LARC.

Sphincter-saving surgery versus abdominoperineal resection in low rectal cancer following neoadjuvant treatment with propensity score analysis

BACKGROUND

Sphincter-saving operation is the treatment of choice in patients with lower rectal cancer, although abdominoperineal resection (APR) is necessary in some cases for adequate oncological outcomes. This study compared the oncologic outcomes of patients with low rectal cancer undergoing APR and intersphincteric resection (ISR) after neoadjuvant chemoradiotherapy (nCRT).

METHODS

We compared 104 patients who underwent ISR for lower rectal cancer between 2008 and 2014 with 79 patients who underwent APR during the same period. Cases in which tumors involved the levator ani muscle or the external anal sphincter, as well as those in which surgeons were unable to obtain a negative distal margin via sphincter-saving operation were excluded. Fifty-two patients who underwent ISR were matched via propensity scoring with 52 patients who underwent APR. The analyzed variables included patient and tumor characteristics and long-term outcomes before and after 1:1 propensity score matching (PSM).

RESULTS

After matching, there were no significant differences between the two groups in clinical stage and tumor distance from anal verge. Short- and long-term outcomes were similar between the two groups. The 5-year disease-free survival rate was 76.3% in the ISR group and 57.8% in the APR group (p = 0.080). The 5-year cancer-specific survival rate was 89.5% in the ISR group and 85.4% in the APR group (p = 0.383).

CONCLUSIONS

This reveals that ISR and APR have similar oncologic outcomes following nCRT in patients with advanced low rectal cancer adjusted for background variables.

Prognostic and predictive value of neutrophil-to-lymphocyte ratio after curative rectal cancer resection: A systematic review and meta-analysis

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has been shown to be associated with poor prognosis in numerous solid malignancies. Here, we quantify the prognostic value of NLR in rectal cancer patients undergoing curative-intent surgery, and compare it with platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR).

METHODS

A comprehensive search of several electronic databases was performed through January 2021, to identify studies evaluating the prognostic impact of pretreatment NLR in patients undergoing curative rectal cancer resection. The endpoints were overall survival (OS), disease-free survival (DFS), and clinicopathologic parameters. The pooled hazard ratio (HR) or odds ratio with 95% confidence interval (CI) were calculated.

RESULTS

Thirty-one studies comprising 7553 patients were assessed. All studies evaluated NLR; thirteen and six evaluated PLR and LMR, respectively. High NLR was associated with worse OS (HR 1.92, 95% CI 1.60-2.30, P < 0.001) and DFS (HR 1.83, 95% CI 1.51-2.22, P < 0.001), and the results were consistent in all subgroup analyses by treatment modality, tumor stage, study location, and NLR cut-off value, except for the subgroups limited to cohorts with cut-off value ≥ 4. The size of effect of NLR on OS and DFS was greater than that of PLR, and similar to that of LMR. Finally, high NLR was associated with lower rate of pathologic complete response.

CONCLUSIONS

In the setting of curative rectal cancer resection, pretreatment NLR correlates with tumor response to neoadjuvant therapy, and along with LMR, is a robust predictor of poorer prognosis. These biomarkers may thus help risk-stratify patients for individualized treatments and enhanced surveillance.

Low MicroRNA-19b Expression Shows a Promising Clinical Impact in Locally Advanced Rectal Cancer

Simple Summary

The establishment of molecular markers to predict response to neoadjuvant chemoradiotherapy (CRT) would help to avoid unnecessary toxicities and surgery delays in the clinical management of locally advanced rectal cancer (LARC) patients. Our aim here was to in-vestigate the clinical impact of miR-19b in this disease. Interestingly, our findings highlight the potential usefulness of miR-19b as a predictor of response to neoadjuvant CRT and outcome, and suggest PPP2R5E as a relevant miR-19b target in LARC.

Abstract

The standard treatment for patients with locally advanced colorectal cancer (LARC) is neoadjuvant 5-fluorouracil (5-FU) based chemoradiotherapy (CRT) followed by surgical mesorectal excision. However, the lack of response to this preoperative treatment strongly compromises patient outcomes and leads to surgical delays and undesired toxicities in those non-responder cases. Thus, the identification of effective and robust biomarkers to predict response to preoperative CRT represents an urgent need in the current clinical management of LARC. The oncomiR microRNA-19b (miR-19b) has been reported to functionally play oncogenic roles in colorectal cancer (CRC) cells as well as regulate 5-FU sensitivity and determine outcome in CRC patients. However, its clinical impact in LARC has not been previously investigated. Here, we show that miR-19b deregulation is a common event in this disease, and its decreased expression significantly associates with lower tumor size after CRT (p = 0.003), early pathological stage (p = 0.003), and absence of recurrence (p = 0.001) in LARC patients. Interestingly, low miR-19b expression shows a predictive value of better response to neoajuvant CRT (p < 0.001), and the subgroup of LARC patients with low miR-19b levels have a markedly longer overall (p = 0.003) and event-free survival (p = 0.023). Finally, multivariate analyses determined that miR-19b independently predicts both patient outcome and response to preoperative CRT, highlighting its potential clinical usefulness in the management of LARC patients.

High Expression of VSTM2L Induced Resistance to Chemoradiotherapy in Rectal Cancer through Downstream IL-4 Signaling

Background

Preoperative chemoradiotherapy (pCRT) is a common and essential therapeutic strategy for patients with locally advanced rectal cancer (LARC), but poor tumor response and therapeutic resistance to chemoradiotherapy have appeared usually among persons and affected those patients' survival prognosis. The resistance to chemoradiotherapy in rectal cancer is difficult to predict. This study was aimed at evaluating the role of V-set and transmembrane domain containing 2 like protein (VSTM2L) in resistance to chemoradiotherapy in rectal cancer.

Methods

Analysis of the GEO profiling datasets of rectal cancer patients receiving pCRT disclosed that VSTM2L as a candidate gene was significantly upregulated in nonresponders of rectal cancer with pCRT. The mRNA and protein expression of VSTM2L was detected by quantitate real-time PCR, western blotting, and immunohistochemistry in six rectal cancer biopsy tissues before pCRT. Furthermore, the rectal cancer patient-derived organoids were cultured to evaluate the association of VSTM2L expression and tumor response to CRT. Overexpression of VSTM2L in cancer cells treated with CRT was analyzed for the function of cell proliferation and viability, clone formation, DNA damage repair, and apoptosis ability. The GSEA and RNA-sequence analysis were used to find the downstream mechanism of VSTM2L overexpression in cells treated with CRT.

Results

The mRNA levels of VSTM2L were significantly downregulated in normal rectal tissues compared to tumor tissues and were upregulated in nonresponders of rectal cancer patients receiving pCRT and positively correlated with poor survival prognosis from GEO datasets. High expression of VSTM2L was significantly associated with tumor regression after pCRT (P = 0.030). Moreover, high expression of VSTM2L reduced γ-H2AX expression in rectal cancer patient-derived organoids treated with CRT. The overexpression of VSTM2L in colorectal cancer cells induced resistance to CRT via promoting cell proliferation and inhibiting apoptosis. The molecular mechanism revealed that the overexpression of VSTM2L induced resistance to CRT through downstream IL-4 signaling affecting the progress of cell proliferation and apoptosis.

Conclusion

The high expression of VSTM2L induced resistance to CRT, and adverse survival outcomes served as a prognostic factor in patients with rectal cancer receiving pCRT, suggesting that VSTM2L high expression may be a potential resistant predictable biomarker for LARC patients receiving pCRT.

Even a partial pathological response is associated with lower relapse rates in patients with operable rectal cancer undergoing neoadjuvant chemotherapy

BACKGROUND

Neoadjuvant chemotherapy to treat locally advanced rectal cancer is an effective therapeutic strategy for the prevention of local recurrence and distant organ metastasis after surgery.

OBJECTIVES

To assess the prognostic significance of histopathological tumor response in rectal cancer patients undergoing neoadjuvant chemotherapy.

METHODS

This study included patients with operable rectal cancer who received neoadjuvant chemotherapy using the FOLFOX regimen (5-fluorouracil, l-leucovorin, and oxaliplatin) in a hospital between February 2012 and November 2017. The main outcome measure was disease-free survival with respect to histopathological response to neoadjuvant chemotherapy in resected specimens.

RESULTS

The median follow-up was 32 months. Of 48 patients treated with neoadjuvant FOLFOX, 24 (50%) were classified as responders, which included two patients with pathological complete response and 22 patients with partial response. The remaining 24 patients (50%) were classified as nonresponders. Responders had a significantly better 3-year disease-free survival than nonresponders (86% vs. 62%, p = .02).

CONCLUSIONS

Patients whose surgical specimens show a pathological complete response or partial response have good oncologic outcomes.

Ten-year survival after pathologic complete response in rectal adenocarcinoma

BACKGROUND

Multimodal treatment is the standard of care for rectal adenocarcinoma, with a subset of patients achieving a pathologic complete response (pCR). While pCR is associated with improved overall survival (OS), long-term data on patients with pCR is limited.

METHODS

This is a single institution retrospective cohort study of all patients with clinical stages II/III rectal adenocarcinoma who underwent neoadjuvant chemoradiation therapy and operative resection (January 1, 2004-December 31, 2017). PCR was defined as no tumor identified in the rectum or associated lymph nodes by final pathology.

RESULTS

Of 370 patients in this cohort, 50 had a pCR (13.5%). For pCR patients, 5-year disease-free survival (DFS) was 92%, 5-year OS was 95%. Twenty-six patients had surgery > 10 years before the study end date, of which 20 had an OS > 10 years (77%) with median OS 12.1 years and 95% alive to date (19/20). Of the 50 pCR patients, there was a single recurrence in the lung at 44.3 months after proctectomy which was surgically resected.

CONCLUSION

For patients with rectal adenocarcinoma that undergo neoadjuvant chemoradiation and surgical resection, pCR is associated with excellent long-term DFS and OS. Many patients live greater than 10 years with no evidence of disease recurrence.

Adjuvant Chemotherapy after Neoadjuvant Chemotherapy and Long-term Outcomes of CAPOX Plus Bevacizumab Followed by TME for High-risk Localized Rectal Cancer

Objectives:

We previously reported the feasibility of neoadjuvant capecitabine and oxaliplatin plus bevacizumab as a treatment for locally advanced rectal cancer (UMIN000003219). The aim of this study is to investigate the prognostic relevance of neoadjuvant chemotherapy followed by total mesorectal resection (TME).

Methods:

Twenty-five patients of our prior multicenter prospective study of neoadjuvant chemotherapy followed by TME enrolled to this study. We analyzed the adjuvant chemotherapy regimen, and the duration between surgery and initial chemotherapy treatment. Five-year progression-free survival and overall survival were estimated using the Kaplan-Meier method.

Results:

Among survivors, the median follow-up time was 66 months. Recurrence occurred in six patients, all of whom had suboptimal tumor regression after neoadjuvant chemotherapy. Five patients died from other causes. The rate of local recurrence and distant metastasis was 17.4% and 8.7%, respectively. Five-year progression-free survival was 70.0%, and 5 year overall survival was 84.0%.

Conclusions:

We report the long-term survival of patients who received neoadjuvant chemotherapy without radiation followed by TME, revealing a generally favorable prognosis.

Improved Outcomes for Rectal Cancer in the Era of Preoperative Chemoradiation and Tailored Mesorectal Excision: A Series of 338 Consecutive Cases

Neoadjuvant chemoradiation (CRT), tailored mesorectal excision, and intraoperative radiotherapy (IORT) have become the leading measures for rectal cancer treatment. The objective of this study was to evaluate early and long-term results of a multimodal treatment model for rectal cancer followed by curative surgery. Prospectively collected hospital records of 338 patients surgically treated for rectal cancer between January 1998 and December 2008 were retrospectively reviewed. Patients with high rectum level cancers and those with middle and low rectum cancers with clinical stage T1 to T2 underwent surgery, whereas those with T3 to T4 and N1 disease at the middle and low rectum received neoadjuvant CRT in 96.2 per cent of cases. Short-course neoadjuvant radiotherapy was not considered for neoadjuvant treatment. Postoperative major complications and mortality rates were 12.7 and 2.3 per cent, respectively. Overall 5-year disease-specific and disease-free survival were 80 and 73.1 per cent, respectively, whereas local recurrence rate was 6.1 per cent. At multivariate analysis, nodal status and circumferential margin status were independently associated with poor survival; local recurrence rates were independently affected by nodal and marginal status and tumor stage. The extent of mesorectal excision should be tailored depending on tumor location and the use of neoadjuvant chemotherapy, combined with IORT in advanced middle and low rectal cancer, leading to remarkable tumor downstaging with excellent prognosis in responding patients.

Analysis of influencing factors of no/low response to preoperative concurrent chemoradiotherapy in locally advanced rectal cancer

The aim of this study is to investigate the influencing factors associated with no/low response to preoperative concurrent chemoradiotherapy (CCRT) for locally advanced rectal cancer (LARC) patients. A total of 79 patients were included in this prospective study. Fifteen factors that might affect the resistance to CCRT were included in this logistic regression analysis, these factors include the general clinical data of patients, the expression status of tumor stem cell marker CD44v6 and the volumetric imaging parameters of primary tumor lesions. We found that the no/low response status to preoperative CCRT was positively correlated with the real tumor volume (RTV), the total surface area of tumor (TSA), and CD44v6 expression, whereas negatively correlated with the tumor compactness (TC). According to the results of logistic regression analysis, two formulas that could predict whether or not no/low response to preoperative CCRT were established. The Area Under Curve (AUC) of the two formulas and those significant measurement data (RTV, TC, TSA) were 0.900, 0.858, 0.771, 0.754, 0.859, the sensitivity were 95.8%, 79.17%, 62.50%, 95.83%, 62.5%, the specificity were 70.9%, 74.55%, 83.64%,47.27%, 96.36%, the positive predictive values were 58.96%, 57.58%, 62.51%,44.23%, 88.23%, the negative predictive values were 97.48%, 89.13%, 83.64%, 96.29%, and 85.48%, respectively.

High neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio predict poor survival in rectal cancer patients receiving neoadjuvant concurrent chemoradiotherapy

This study explored the prognostic value of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in rectal cancer patients receiving neoadjuvant concurrent chemoradiotherapy (CCRT).Between January 2006 and December 2016, 184 patients with newly-diagnosed rectal cancer receiving neoadjuvant CCRT were enrolled. Risk of overall survival (OS) and disease-free survival (DFS) were calculated using the Kaplan-Meier method and Cox proportional hazard models. Stratified survival analyses were also performed between post-neoadjuvant pathological (yp) stage.The mean follow-up time was 72.73 ± 36.82 months. High- and low-NLR patients differed significantly in both 5-year DFS (P = .026) and OS (P = .016). High- and low-PLR patients differed significantly in 5-year DFS (P = .011) but not OS (P = .185). Multivariate analyses revealed worse 5-year DFS (adjusted HR [aHR] = 2.8; 95% CI: 1.473-5.41; P = .002) and 5-year OS (aHR = 1.871; 95%CI: 1.029-3.4; P = .04) in the high-NLR group after adjusting for covariates. After adjustments, the high-PLR group had inferior 5-year DFS (aHR = 2.274; 95%CI: 1.473-5.419; P = .038) but not 5-year OS (aHR = 1.156; 95%CI: 0.650-2.056; P = .622). Further stratified analysis indicated that yp stage II and III patients with high NLR had worse 5-year DFS (aHR = 2.334; 95% CI: 1.158-4.725; P = .018) and OS (aHR = 2.226; 95% CI: 1.165-4.251; P = .015). Additionally, yp stage II and III patients with high PLR had inferior 5-year DFS (aHR = 2.012; 95% CI: 1.049-3.861; P = .036).Pre-CCRT NLR and PLR are independent prognostic factors for rectal cancer patients and could be used as a potential biomarker to identify high-risk patients for more intense treatment and care.

Short-Term Clinical and Oncological Outcome of Prolonging Operation Interval After Neoadjuvant Chemoradiotherapy for Locally Advanced Middle and Low Rectal Cancer

Purpose

The purpose of this study is to evaluate the short-term clinical and oncological outcome of prolonging operation interval to 11 weeks after the end of radiotherapy for locally advanced middle and low rectal cancer.

Methods

A total of 123 patients with stage II/III (cT3/T4 or N+) low and middle rectal cancer who had undergone operation after neoadjuvant chemoradiotherapy were selected. According to the interval time between the last radiotherapy and operation, they were assigned to a short-interval group (SG, <11 weeks, n=66) and long-interval group (LG, ≥11 weeks, n=57). The relations among interval time and short-term clinical outcome and oncological outcome were analyzed.

Results

The analysis found that basic information, clinical characteristics, and preoperative treatment between the two groups had no significant difference. There were no differences in operation time, estimated intraoperative blood loss and postoperative complications. The rate of sphincter preservation in the low and middle rectum was 66.7% in the short-interval group and 59.7% in the long-interval group (P=0.42). The incidence of anastomotic leak in the long-interval group was higher than that in the short-interval group (P=0.08). There was no significant difference in the recovery time of intestinal function and median duration of hospitalization between the two groups. The pathological complete remission rate was 17.07%. Multivariate analysis showed interval time had no influence on pathological complete remission. There was no significant difference in 3-year overall survival and 3-year disease-free survival between the two groups. The risk of recurrence and metastasis in patients with positive lymph nodes was higher than those with negative lymph nodes (P<0.05), HR=4.812 (95% CI 2.4–9.648).

Conclusion

Prolonging the interval time of operation to 11 weeks after neoadjuvant chemoradiotherapy for middle and low rectal cancer does not improve the pathologic complete remission, morbidity, and mortality. There was no significant effect on oncologic outcome after prolonging the operation interval. Therefore, it is safe to prolong the interval of operation to 11 weeks.

Low BRCA2 expression predicts poor prognoses in patients with rectal cancer receiving chemoradiotherapy

OBJECTIVE

Neoadjuvant concurrent chemoradiotherapy (CCRT) followed by surgery is now the standard care for patients with advanced rectal cancer. Because a certain proportion of these patients have poor response to CCRT, the risk stratification of survival outcomes needs to be investigated. DNA repair responses in tumor cells can regulate malignant potential and therapy resistance. In this study, we analyzed the clinical significance of principal DNA repair effectors in patients with rectal cancer.

METHODS

We applied data mining for DNA repair pathways in a published transcriptome for rectal cancer cases, and identified that tumors with BRCA2 downregulation correlated with poor response to CCRT. We next examined BRCA2 expression by using immunohistochemistry staining in tumor tissues of 172 patients with rectal cancer. The correlation between BRCA2 expression levels and clinical variables was further analyzed in this rectal cancer cohort.

RESULTS

Among clinical and pathological factors, low BRCA2-expression was significantly correlated with higher pre-treatment (Tx) tumor status (P = .013), post-Tx tumor (P < .001) and nodal status (P = .044), vascular invasion (P = .008), and poor tumor regression grades (P < .001). In analyses of survival outcomes, patients with low BRCA2-expression were associated with shorter local recurrence-free survival (LRFS; P = .0005) and disease-specific survival (P = .0269). Multivariate analyses confirmed the independent prognostic value of low BRCA2-expression for shorter LRFS (P = .045, hazard ratio = 4.695).

CONCLUSION

Low BRCA2-expression is a significant predictor for tumors in advanced stages, poor response to CCRT, and shorter survivals in patients with rectal cancer. Poly (adenosine diphosphate-ribose) polymerase inhibitors targeting DNA repair response in cells have demonstrated clinical efficacy in BRCA2-mutated patients with cancer. Further studies evaluating the efficacy of CCRT combined with these inhibitors in low BRCA2-expressing rectal cancers are encouraged.

Controversies in Rectal Cancer Treatment and Management

Incorporation of new treatment modalities has significantly increased the complexity of the treatment and management of rectal cancer, including perioperative therapy for local advanced disease and organ preservation for those with response to the preoperative treatment. This review may help practitioners better understand the rationale and selection.

Treatment of stage I-III rectal cancer: Who is refusing surgery?

BACKGROUND AND OBJECTIVES

Surgical resection is a cornerstone in the management of patients with rectal cancer. Patients may refuse surgical treatment for several reasons although the rate of refusal is currently unknown.

METHODS

The National Cancer Database was utilized to identify patients with stage I-III rectal cancer. Patients who refused surgical resection were compared to patients who underwent curative resection.

RESULTS

A total of 509 (2.6%) patients with stage I and 2082 (3.5%) patients with stage II/III rectal cancer refused surgery. In multivariable analysis for stage I disease, older age, Black race, and Medicaid/no insurance were independent predictors of surgery refusal. Patients were less likely to refuse surgery if they had a higher income or lived further distances from the treatment facility. In multivariable analysis for stage II/III disease, older age, Black race, insurance other than private, and rural county were independent predictors of surgery refusal. Patients were less likely to refuse surgery if they had higher Charlson comorbidity scores, lived further distances from the treatment facility, or underwent chemoradiation. There was a significant decrease in survival for patients refusing surgery compared to patients undergoing recommended surgery.

CONCLUSIONS

A small proportion of patients refuse surgery for rectal cancer, and this treatment decision significantly affects survival.

The impact of tumor regression grade on long-term survival in locally advanced rectal cancer treated with preoperative chemoradiotherapy

PURPOSE

The aim of this study is to investigate the prognostic effect of tumor regression grade (TRG) on long-term survival in locally advanced rectal cancer treated with preoperative chemoradiotherapy.

METHODS

Medical records of 182 patients with locally advanced rectal cancer, who were treated with preoperative chemoradiotherapy followed by surgery between 2002 and 2016, were retrospectively reviewed. TRG was classified into five categories based on the pathological response as follows - TRG1: no viable cancer cell, TRG2: single cancer cell or small groups of cancer cells, TRG3: residual tumor outgrown by fibrosis, TRG4: residual tumor outgrowing fibrosis, TRG5: diffuse residual tumor without regression. TRG1, (TRG2+TRG3), and (TRG4+TRG5) were grouped as complete response, intermediate response, and no response, respectively.

RESULTS

Of the 182 patients with locally advanced rectal cancer, 112 (61.5%) were male. The mean age was 54.4 (range, 25-87) years. The total number of patients in complete response, intermediate response, and no response group was 24 (13.2%), 105 (57.7%), and 53 (29.1%), respectively. The corresponding five-year relapse-free survival and overall survival rates were 79.8%-92.3%, 74.7%-79.4%, and 55.7%-55.8%, respectively (p < 0.05 for relapse-free survival, p < 0.05 for overall survival). According to ypTNM stage, there was no significant difference in relapse-free survival among TRG groups in ypStage I and II patients (p > 0.05). In ypStage III patients, relapse-free survival was 62 months in no response group vs. not reached in intermediate response group (p < 0.05). According to the ypTNM, there was no significant difference in overall survival among TRG groups in ypStage I, II, and III patients (p > 0.05). In the multivariate analysis, pathological complete response was found to be an independent variable for relapse-free survival and overall survival (hazard ratio (95% confidence interval), 0.34 (0.17-6.77), 0.39 (0.18-0.83), respectively).

CONCLUSION

This study showed that patients with pathological complete response to preoperative chemoradiotherapy had longer relapse-free survival and overall survival rates than those with residual disease.

Outcomes of surgical treatment for patients with distal rectal cancer: A retrospective review from a single university hospital

INTRODUCTION AND AIM

Surgery for distal rectal cancer (DRC) can be performed with or without sphincter preservation. The aim of the present study was to analyze the outcomes of two surgical techniques in the treatment of DRC patients: low anterior resection (LAR) and abdominoperineal resection (APR).

METHODS

Patients with advanced DRC that underwent surgical treatment between 2002 and 2012 were evaluated. We compared the outcomes of the type of surgery (APR vs LAR) and analyzed the associations of survival and recurrence with the following factors: age, sex, tumor location, lymph nodes obtained, lymph node involvement, and rectal wall involvement. Patients with distant metastases were excluded.

RESULTS

A total of 148 patients were included, 78 of whom were females (52.7%). The mean patient age was 61.2years. Neoadjuvant chemoradiation therapy was performed in 86.5% of the patients. APR was performed on 86 (58.1%) patients, and LAR on 62 (41.9%) patients. No differences were observed between the two groups regarding clinical and oncologic characteristics. Eighty-seven (62%) patients had pT3-4 disease, and 41 patients (27.7%) had lymph node involvement. In the multivariate analysis, only poorly differentiated tumors (P=.026) and APR (P=.009) correlated with higher recurrence rates. Mean follow-up time was 32 (16-59.9) months. Overall 5-year survival was 58.1%. The 5-year survival rate was worse in patients that underwent APR (46.5%) than in the patients that underwent LAR (74.2%) (P=.009).

CONCLUSIONS

Patients with locally advanced DRC that underwent APR presented with a lower survival rate and a higher local recurrence rate than patients that underwent LAR. In addition, advanced T/stage, lymph node involvement, and poor tumor differentiation were associated with recurrence and a lower survival rate, regardless of the procedure.

Importance of the neoadjuvant rectal (NAR) score to the outcome of neoadjuvant chemotherapy alone for locally advanced rectal cancer

PURPOSE

The neoadjuvant rectal (NAR) score is a promising indicator of survival after preoperative chemoradiotherapy for rectal cancer. However, its effectiveness after neoadjuvant chemotherapy (NAC) alone has not been fully investigated.

METHODS

We analyzed data retrospectively on 61 patients with rectal cancer, who received NAC followed by surgical resection between 2010 and 2015, and evaluated the impact of the NAR score on survival.

RESULTS

The median NAR score was 14.9. Of the 61 patients, 13, 35, and 13 were classified as having NAR-low (< 8), NAR-intermediate (8-16), and NAR-high (> 16) scores, respectively. The median observation period was 49.0 months. According to the NAR score, the 3-year DFS in the NAR-low group was 100%, which was significantly better than that in the NAR-intermediate (64.8%, p = 0.041), and NAR-high (61.5%, p = 0.018) groups. When the NAR-intermediate and NAR-high groups were investigated as a single high-risk group, the 3-year DFS of the patients who received adjuvant chemotherapy was 88.7%, which was significantly better than that of the patients who did not receive adjuvant chemotherapy (53.3%, p = 0.042).

CONCLUSIONS

The NAR score may predict the DFS and could serve as a favorable indicator of adjuvant chemotherapy after NAC alone.

Intraoperative radiotherapy as an immediate adjuvant treatment of rectal cancer due to limited access to external-beam radiotherapy

BACKGROUND

Neoadjuvant external-beam radiotherapy (EBRT) with concomitant chemotherapy is the current standard-of-care for locally-advanced rectal cancer. Intraoperative radiotherapy (IORT) is to date only recommended for pelvic recurrences or incompletely resectable tumors. We here report on patients with stage II/III rectal cancer that were treated with IORT in a regional Russian university center due to limited access to EBRT.

METHODS

We retrospectively analyzed data from patients that were diagnosed with locally-advanced rectal cancer and underwent surgery from December 2012 to October 2016 at a regional oncological center in Russia (Krasnodar). During this period, access to EBRT was limited due to a temporary lack of a sufficient number of EBRT facilities. Patients unable to travel to a distant radiotherapy site received IORT alone, those that could travel received neoadjuvant external beam (chemo-) radiotherapy. Factors of interest were tumor stage, tumor differentiation, resection status, surgery type and neoadjuvant or adjuvant chemotherapy. We assessed local progression-free survival (L-PFS), PFS and overall survival (OS).

RESULTS

A total of 172 patients were included in this analysis. Of those, 92 (53.5%) were treated with IORT alone (median dose: 15 Gy [8.4-17 Gy]) and 80 (46.5%) received both neoadjuvant EBRT (median dose: 50.4 Gy [40-50.4 Gy]) and IORT (median dose: 15 Gy [15-17 Gy]). The median age was 65 years [33-82]. The median follow-up was 23 months [0-63 months]. The incidence of toxicity was low in both groups with an overall complication rate of 5.4%. Local PFS at 4 years was comparable with 59.4% in the IORT group and 65.4% in the IORT/EBRT group (p = 0.70). Similarly, there was no difference in OS or PFS (p = 0.66, p = 0.51, respectively).

CONCLUSIONS

IORT is a valuable option for patients with locally-advanced rectal cancer in the absence of access to EBRT.

Pathological Tumor Regression Grade Classifications in Gastrointestinal Cancers: Role on Patients' Prognosis

Preoperative chemotherapy or combined radiotherapy and chemotherapy (CRT), followed by surgery, represents the standard approach for locally advanced esophageal, gastric, and rectal carcinomas. To adequately evaluate the effects of neoadjuvant CRT in the resection specimens, several histopathologic tumor regression grade (TRG) scoring systems have been introduced into clinical practice. The primary goal of these TRG systems relies on a correct prognostic stratification of patients in the attempt to help clinical decision-making and influence surgical strategies, postoperative adjuvant therapies, and surveillance intensity. However, most TRG systems suffer from poor reproducibility and low interobserver concordance rates. Many efforts have been made in the identification of alternative, robust, simple, and universally accepted TRG scoring systems, which would help in the comparison of different treatment strategies and in the standardization of multimodal therapies. The aim of this review is to analyze the most commonly used TRG systems in gastrointestinal cancers highlighting their pitfalls and usefulness, depending on the tumor type.

Is follow-up still mandatory more than 5 years after surgery for colorectal cancer?

PURPOSE

The aim of this study was to assess if to prolong follow-up (FU) more than 5 years after surgery for colorectal cancer (CRC) is justified or not.

METHODS

Patients who underwent surgery for a CRC before 2013 and without any tumor recurrence (or synchronous metastases) during the first 5 years after surgery were identified from our database and included.

RESULTS

Between 1996 and 2012, 121 patients operated for rectal (RC) (median of FU of 84 months; range 60-211) and 97 with colonic cancer (CC) (median of FU of 78 months; range 60-139), without any tumor recurrence (or synchronous metastases) during the first 5 years after surgery, presented a late tumor recurrence: 13/121 RC (10.7%) versus 2/97 CC (2.1%) (p = 0.014); 8/13 recurrences in RC (61.5%) were observed after neoadjuvant radiochemotherapy, and 9/13 (69.2%) in pN0 tumors. Among the 13 recurrences, 3 had both local and metastatic recurrences (23%), 5 an isolated local recurrence (38.5%) and 5 an isolated metastatic recurrence (38.5%). After surgery for CC, the 2 recurrences were observed in patients with T3N0 tumors.

CONCLUSION

After surgery for a CRC, in patients without tumor recurrence during the first 5 years after surgery, follow-up after 5 years must be continued in rectal cancer patients because of a 10.7% rate of late recurrence. On the opposite, after surgery for colon cancer the 2% rate of late recurrence after 5 years suggested that only patients with pT3-T4 colonic cancer could probably be followed more than 5 years after surgery.

Over-Expression of CHD4 Is an Independent Biomarker of Poor Prognosis in Patients with Rectal Cancers Receiving Concurrent Chemoradiotherapy

Neoadjuvant concurrent chemoradiotherapy (CCRT), followed by radical proctectomy, is the standard treatment for locally advanced rectal cancer. However, a poor response and therapeutic resistance continue to occur despite this treatment. In this study, we analyzed the microarray datasets (GSE68204) of rectal cancer from the Gene Expression Omnibus database, and identified CHD4 as one of the most significantly up-regulated genes among all subunits of the nucleosome remodeling and histone deacetylation (NuRD) complex, in non-responders to CCRT, among locally advanced rectal cancer (LARC) patients. We confirmed the predictive and prognostic significance of CHD4 expression in CCRT treatment, and its correlation with other clinicopathological features, such as tumor regression grade (TRG), therapeutic response, and patient survival. This was carried out by immunohistochemical studies on endoscopic biopsy tissues from 172 rectal cancer patients, receiving neoadjuvant concurrent chemoradiotherapy (CCRT). A high expression of CHD4 was significantly associated with pre-treatment tumor status (p < 0.001) and lymph node metastasis (p < 0.001), post-treatment tumor status (p < 0.001), and lymph node metastasis (p < 0.001), vascular invasion (p = 0.042), and tumor regression grade (p = 0.001). A high expression of CHD4 could also predict poor disease-specific survival and metastasis-free survival (log-rank test, p = 0.0373 and p < 0.0001, respectively). In multivariate Cox proportional-hazards regression analysis, CHD4 overexpression was an independent factor of poor prognosis for metastasis-free survival (HR, 4.575; 95% CI, 1.717–12.192; p = 0.002). By in vitro studies, based on cell line models, we also demonstrated that, the overexpression of CHD4 induced radio-resistance in microsatellite instability-high (MSI-H) colorectal cells (CRCs). On the contrary, the knockdown of CHD4 enhanced radiosensitivity in microsatellite stable (MSS) CRCs. Altogether, we have identified CHD4 as an important regulator of radio-resistance in both MSI-H and MSS CRC cell lines.

Total neoadjuvant therapy in locally advanced rectal cancer: Role of systemic chemotherapy

For the past several decades, disease-related outcomes, particularly local recurrence rate, in patients with locally advanced rectal cancer have significantly improved as a result of advancement of surgical technique and implementation of neoadjuvant chemoradiation. However, distant metastasis remains unresolved, being a significant cause of cancer death. To focus on micrometastases early in the course of multimodal treatment, delivering systemic chemotherapy in the neoadjuvant setting is emerging. Also, driven by patient demand and interest in preserving quality of life, upfront chemotherapy prior to surgery serves as a strategy for organ preservation in the management of rectal cancer. Herein, currently available literature on different methods and strategies of the multimodal approach is critically appraised.

A novel LARCassigner3 classification predicts outcomes in patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy: a retrospective training and validation analysis

Purpose: To build and validate a predictive model of outcome for patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy. Materials and methods: We developed a LARCassigner3 classifier based on tumor and paired normal tissues of patients treated with neoadjuvant chemoradiation and surgery from January 2007 to December 2012 in Fudan University Shanghai Cancer Center. Excluding 23 pairs of tissues failed in the RNA quality test, rested 197 patients were divided into discovery (n=98) and validation (n=99) cohorts randomly. Median follow-up time was 58 months. We used the Kaplan-Meier method to estimate disease-free survival (DFS), overall survival (OS), local recurrent, and distant metastatic rate We constructed a multivariate Cox model to identify the variables independently associated with progression-free and OS. Results: We identified three classifier genes related to relevant colorectal cancer features (CXCL9, SFRP2, and CD44) that formed the LARCassigner3 classifier assay. In the discovery set, the median DFS was 48.1 months (95% confidence interval (CI) 47.3-49.5) in the low-risk group and 23.4 months (95% CI 22.1-24.8) in the high-risk group (p=0.0134); the median OS was 39.2 months (95% CI 38.4-40.3) in the high-risk group and 19.1 months (95% CI 18.3-20.7) in the low-risk group (p=0.0134); 5-year distant metastasis was 13.9% (95% CI 9.0-21.3) in the low-risk group and 49.8% (95% CI 38.7-60.9) in the high-risk group (p=0.0072). Additionally, the different responses to neoadjuvant chemoradiotherapy and the LARCassigner3 low-risk and high-risk groups was statistically significant (p=0.004) in the discovery cohort. Similar results were obtained in the internal evaluation cohort. Conclusions: Patients with LARCassigner3 low-risk tumors were associated with a good prognosis. The clinical utility of using LARCassigner3 subtyping for the identification of patients for neoadjuvant chemoradiotherapy requires validation in dependent clinical trial cohorts.

What are the most important prognostic factors in patients with residual rectal cancer after preoperative chemoradiotherapy?

Background

We aimed to establish robust histoprognostic predictors on residual rectal cancer after preoperative chemoradiotherapy (CRT).

Methods

Analyzing known histoprognostic factors in 146 patients with residual disease allows associations with patient outcome to be evaluated.

Results

The median follow-up time was 77.8 months, during which 59 patients (40.4%) experienced recurrence and 41 (28.1%) died of rectal cancer. On univariate analysis, residual tumor size, ypT category, ypN category, ypTNM stage, downstage, tumor regression grade, lymphatic invasion, perineural invasion, venous invasion, and circumferential resection margin (CRM) were significantly associated with recurrence free survival (RFS) or/and cancer-specific survival (CSS) (all p<0.005). On multivariate analysis, higher ypTNM stage and CRM positivity were identified as independent prognostic factors for RFS (ypTNM stage, p=0.024; CRM positivity, p<0.001) and CSS (p=0.022, p=0.017, respectively). Furthermore, CRM positivity was an independent predictor of reduced RFS and CSS, irrespective of subgrouping according to downstage (non-downstage, p<0.001 and p<0.001; downstage, p=0.002 and p=0.002) or lymph node metastasis (non-metastasis, p<0.001 and p=0.001; metastasis, p<0.001 and p<0.001).

Conclusion

CRM status may be as powerful as ypTNM stage as a prognostic indicator for patient outcome in patients with residual rectal cancer after preoperative CRT.

Prognostic Impact of Perineural Invasion in Rectal Cancer After Neoadjuvant Chemoradiotherapy

BACKGROUND

Perineural invasion (PNI) has emerged as an important factor related to colorectal cancer spread; however, the impact of neoadjuvant chemoradiotherapy (nCRT) on PNI remains unclear. Herein, we investigated the prognostic value of PNI, along with lymphovascular invasion (LVI), in rectal cancer patients treated with nCRT.

METHODS

This single-center observational study of pathologic variables, including PNI and LVI, analyzed 1411 invasive rectal cancer patients (965 and 446 patients treated with primary resection and nCRT, respectively).

RESULTS

The overall detection rates of LVI and PNI were 16.7 and 28.8%, respectively. The incidence of LVI was significantly lower in patients treated with nCRT (8.1 vs. 20.6%, P < .001); this was confirmed by multivariate analysis. However, PNI was not affected by nCRT (with nCRT 28.3% vs. without nCRT 29.1%, P = .786). In the 446 patients with nCRT, multivariate analysis revealed that PNI was an independent prognostic factor for both disease-free survival (DFS) and overall survival (OS). For the prediction of both 5-year DFS and OS, the C-index for the combinations of T-stage with the PNI (TPNI) system showed favorable result, especially in patients with a total number of harvested lymph nodes <8.

CONCLUSION

PNI is a meaningful prognostic factor for rectal cancer patients treated with nCRT, especially when <8 lymph nodes are harvested. The lack of influence of nCRT on the PNI incidence suggests that residual tumor cells with PNI are more radioresistant or biologically aggressive than those without.

Good response to neoadjuvant chemoradiotherapy predicts good oncological outcome in locally advanced rectal cancer

BACKGROUND

After pre-operative concurrent long course chemoradiotherapy (CRT), pathologic complete response (pCR) has been reported with better oncologic outcomes in many articles, whether a moderate response (TRG1) can translate into good clinical outcome remains uncertain.

METHODS

A total of 132 locally advanced rectal cancer patients with neoadjuvant chemoradiotherapy followed by radical surgery were recruited. Their clinicopathologic characteristics and clinical records were retrospectively reviewed. The association between clinicopathologic parameters and pathological response was conducted, and the multivariable analysis of the association between pathologic response and survival was performed.

RESULTS

With a median follow-up of 21.5 months, gender was the only factor associated with pCR (TRG0), while dual-agent chemotherapy regimen was linked with a lower likelihood of good response (TRG0-1). Good response (TGR0-1) remained significant associated with overall survival (OS) and disease-free survival (DFS) after multivariate adjustment. TRG1 was linked with better DFS compared with TRG2-3.

CONCLUSIONS

Patients with post-CRT good response (TRG0-1) demonstrate an excellent local and remote control, especially with those non-pCR patients (TRG1) getting better outcomes.