Randomized phase 3 trial comparing preoperative and postoperative chemoradiotherapy with capecitabine for locally advanced rectal cancer

"Defendit Numerus": A Pooled Analysis of 6145 Locally Advanced Rectal Cancer Treated with Preoperative Chemoradiotherapy

Objective: The optimal management of rectal cancer remains a subject of ongoing research. This meta-analysis of individual patient data assessed the benefit of chemoradiotherapy (fluorouracil-based) in local advanced rectal cancer: disease-free survival and overall survival. Methods: We pooled the data of 6145 patients from 24 studies of rectal cancer who received neoadjuvant radiotherapy with concomitant fluorouracil or capecitabine and surgery. The PRISMA 2020 abstract checklist was followed. Individual participant survival was reconstructed with an algorithm from published Kaplan-Meier curves. Results: The median OS was not reached; the mean survival time was 135.4 months (127.9-141.5). The median DFS was 176.9 months, and the mean disease-free survival time was 122.6 months (111.7-131.9). Conclusions: We provided a benchmark for future studies on rectal cancer treatment. The present results can be used in decision-making for locally advanced rectal cancer patients.

Predicting survival in locally advanced rectal cancer with effective chemoradiotherapy response

BACKGROUND

Locally advanced rectal cancer patients often display favorable responses and favorable oncologic outcomes. Due to the low recurrence rate, there is scarcity of studies investigating the prognostic factors influencing their survival. Therefore, our study sought to assess the prognostic factors associated with survival in rectal cancer patients who achieved either a pathologic complete response or a pathologic stage I after neoadjuvant chemoradiotherapy combined with radical resection.

METHODS

In this retrospective study, we analyzed data from cohort of 1394 patients diagnosed with locally advanced rectal cancer who underwent neoadjuvant chemoradiotherapy combined with total mesorectal excision from January 2008 to April 2017. Finally, we selected 474 (34.2 %) who exhibited either a pathologic complete response or attained pathologic stage I following the treatment. Subsequently, we analyzed the prognostic factors influencing disease-free and overall survival.

RESULTS

A total of 161 (34 %) achieved a pathologic complete response. Our analysis revealed that circumferential resection margin and the administration of adjuvant chemotherapy were prognostic factors for disease-free survival (p = 0.011, p = 0.022). Furthermore, factors influencing overall survival included the clinical N stage and administration of adjuvant chemotherapy (p = 0.035, p = 0.015).

CONCLUSION

In conclusion, the circumferential resection margin, clinical N stage, and administration of adjuvant chemotherapy were prognostic factors for survival in patients showing good response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer. For patients with a positive circumferential resection margin and clinical N (+) stage, intensive follow-up might be needed to achieve favorable oncologic outcomes. Also, we recommend considering adjuvant chemotherapy as a beneficial treatment approach for these patients.

Anus preservation in low rectal adenocarcinoma based on MMR/MSI status (APRAM): a study protocol for a randomised, controlled, open-label, multicentre phase III trial

BACKGROUND

Anus preservation has been a challenge in the treatment of patients with low rectal adenocarcinoma (within 5 cm from the anal verge) because it is difficult to spare the anus with its functioning sphincter complex under the safe margin of tumour resection. Patients with dMMR/MSI-H can achieve a favourable complete response (CR) rate by using a single immune checkpoint inhibitor. For patients with pMMR/MSS/MSI-L, intensified neoadjuvant three-drug chemotherapy may be the preferred option for anal preservation. In addition, the watch and wait (W&W) strategy has been proven safe and feasible for patients with rectal cancer who achieve a clinical complete response (cCR). Therefore, we initiated this clinical trial to explore the optimal neoadjuvant treatment pattern for patients with low locally advanced rectal cancer (LARC) with different MMR/MSI statuses, aiming to achieve a higher cCR rate with the W&W strategy and ultimately provide more patients with a chance of anus preservation.

METHODS

This is a randomised, controlled, open-label, multicentre phase III trial. Patients with clinical stage T2-4 and/or N + tumours located within 5 cm from the anal verge are considered eligible. Based on the results of pathological biopsy, the patients are divided into two groups: dMMR/MSI-H and pMMR/MSS. Patients in the dMMR/MSI-H group will be randomly allocated in a 1:1 ratio to either arm A (monoimmunotherapy) or arm B (short-course radiotherapy followed by monoimmunotherapy). Patients in the pMMR/MSS group will be initially treated with long-term pelvic radiation with concurrent capecitabine combined with irinotecan. Two weeks after the completion of chemoradiotherapy (CRT), the patients will be randomly allocated in a 1:1 ratio to arm C (XELIRI six cycle regime) or arm D (FOLFIRINOX nine cycle regime). The irinotecan dose will be adjusted according to the UGT1A1-genotype. After treatment, a comprehensive assessment will be performed to determine whether a cCR has been achieved. If achieved, the W&W strategy will be adopted; otherwise, total mesorectal excision (TME) will be performed. The primary endpoint is cCR with the maintenance of 12 months at least, determined using digital rectal examination, endoscopy, and rectal MRI or PET/CT as a supplementary method.

DISCUSSION

APRAM will explore the best anus preservation model for low LARC, combining the strategies of consolidation chemotherapy, immunotherapy, and short-course radiotherapy, and aims to preserve the anus of more patients using W&W. Our study provides an accurate individual treatment mode based on the MMR/MSI status for patients with low LARC, and more patients will receive the opportunity for anus preservation under our therapeutic strategy, which would transform into long-term benefits.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05669092 (Registered 28th Nov 2022).

The impact of intensity-modulated radiotherapy in conjunction with chemotherapy on proximal pT3N0 rectal cancer patients after total mesorectum excision

BACKGROUND

This study aimed to ascertain if the incorporation of intensity-modulated radiotherapy (IMRT) with chemotherapy (CTx) offered any advantages for patients diagnosed with stage pT3N0 rectal cancer located in the proximal (upper) region following a complete total mesorectum excision (TME).

METHODS

We retrospectively examined medical records of stage II/III rectal cancer patients who had undergone CTx or concurrent chemoradiation (CCRT) with IMRT after a successful TME. We juxtaposed a variety of survival outcomes across two patient cohorts. Each outcome was further classified according to Gunderson's risk stratification between proximal and distal (middle and low) rectal cancer patients, and we evaluated the factors associated with each outcome.

RESULTS

The median follow-up duration was 4.9 years. Our research comprised 236 rectal adenocarcinoma patients treated at our institution between 2007 and 2019. They received either the CTx (n = 135) or the CCRT (n = 101) with 10-year locoregional recurrence-free survival (LRRFS) of 90.1% and 96.1%, respectively (p = 0.163). However, after performing multivariate adjustments, a pattern emerged hinting at a better LRRFS for the CCRT group (p = 0.052). Perforation had a strong correlation with locoregional recurrence. No significant differences were observed in other survival between the two treatment arms and their respective subgroups. The CCRT group witnessed significantly higher immediate and chronic complications with p = 0.007 and 0.009, respectively. The CCRT group had two secondary cancer-related fatalities (2%, one attributed to IMRT), and another reported by the CTx group (1%). The sole classified locoregional recurrence within the cohort of 37 individuals treated with CTx for proximal pT3N0 rectal cancer was, in fact, the development of sigmoid colon cancer.

CONCLUSION

The results suggest that for patients with proximal pT3N0 rectal cancer post-TME, IMRT is better when not combined with CTx, except in highly perilous scenarios or those involving perforation.

Retrospective Evaluation of the Impact of Dose Escalation Using Pre-operative Simultaneous Integrated Boost Volumetric Modulated Arc Therapy on the Outcome of Locally Advanced Rectal Cancer Patients

PURPOSE

Evaluating the outcome of pre-operative simultaneous integrated boost volumetric modulated arc therapy (SIB-VMAT) concomitant with capecitabine in patients diagnosed with locally advanced rectal cancer (LARC) at King Faisal Specialist Hospital and Research Centre (KFSH&RC), Riyadh, Saudi Arabia, during the period January 2013-December 2019.

RESULTS

A total of 134 patients were enrolled. The median age at diagnosis was 59 years. All patients received pre-operative concurrent chemo-radiation therapy (CCRT) using SIB-VMAT with oral capecitabine. Neoadjuvant chemotherapy was administered prior to CCRT in 32 patients (23.9%). The dose of radiation was 55 Gy in 94 patients (70.1%), while 40 patients (29.9%) received 50 Gy. All patients completed the CCRT treatment without breaks. No records of acute and late grade III and IV toxicities. Curative surgery was performed in all patients with a median interval of 11 (6-52) weeks between the end of CCRT and the date of surgery. No reported 30-day postoperative mortality and no grade III and IV Clavien-Dindo complications. PCR was reported in 26 patients (19.4%), while pathologically negative nodes (pN0) were achieved in 103 patients (76.9%). Adjuvant chemotherapy was utilized in 57 patients (42.5%). The 5-year local recurrence-free survival (LRFS), disease-free survival (DFS), and overall survival (OS) were 93.2%, 67.1%, and 87.3%, respectively. Only tumor regression grade (TRG) was significantly correlated with LRFS, (p value 0.043). On multivariate analysis, only TRG and achievement of pN0 were significantly correlated with DFS (p value < 0.001).

CONCLUSION

Dose escalation utilization (SIB-VMAT) in the pre-operative treatment of LARC is well tolerated and provides effective local control.

Is Nonoperative Management of Rectal Cancer Feasible?

During the past decade, the treatment of locally advanced rectal cancer (LARC) has become more complex. Total neoadjuvant treatment (TNT) has increased the rates of both clinical and pathologic complete response, resulting in improved long-term oncological outcomes. The feasibility to implement nonoperative management (NOM) depends on solving current challenges such as how to correctly identify the best candidates for a NOM without compromising oncologic safety. NOM should be part of the treatment discussion of LARC, considering increasing rates of clinical complete response, potential quality of life gains, avoidance of surgical morbidity, and patient preferences.

Radiomics Approaches for the Prediction of Pathological Complete Response after Neoadjuvant Treatment in Locally Advanced Rectal Cancer: Ready for Prime Time?

In recent years, neoadjuvant therapy of locally advanced rectal cancer has seen tremendous modifications. Adding neoadjuvant chemotherapy before or after chemoradiotherapy significantly increases loco-regional disease-free survival, negative surgical margin rates, and complete response rates. The higher complete rate is particularly clinically meaningful given the possibility of organ preservation in this specific sub-population, without compromising overall survival. However, all locally advanced rectal cancer most likely does not benefit from total neoadjuvant therapy (TNT), but experiences higher toxicity rates. Diagnosis of complete response after neoadjuvant therapy is a real challenge, with a risk of false negatives and possible under-treatment. These new therapeutic approaches thus raise the need for better selection tools, enabling a personalized therapeutic approach for each patient. These tools mostly focus on the prediction of the pathological complete response given the clinical impact. In this article, we review the place of different biomarkers (clinical, biological, genomics, transcriptomics, proteomics, and radiomics) as well as their clinical implementation and discuss the most recent trends for future steps in prediction modeling in patients with locally advanced rectal cancer.

Long-term adverse effects and healthcare burden of rectal cancer radiotherapy: systematic review and meta-analysis

BACKGROUND

As rectal cancer survival increases, more patients survive with potentially severe, long-term gastrointestinal and genitourinary complications from radiotherapy. The burden of these complications for patients and healthcare services is unclear, which this review aims to quantify.

METHODS

Systematic search of Medline and Embase for randomized-controlled trials (RCTs) and multicentre observational studies published since 2000, reporting hospitalization/procedural intervention for long-term (>6 months post-treatment) gastrointestinal or genitourinary complications after radiotherapy and surgery for rectal cancer. Prevalence values were pooled in a meta-analysis assuming random effects. Organ-preservation patients were excluded.

RESULTS

4044 records screened; 24 reports from 23 studies included (15 RCTs, 8 Observational), encompassing 15 438 patients. Twenty-one studies (median follow-up 60 months) reported gastrointestinal complications post-radiotherapy: pooled prevalence 11% (95% confidence interval (95% CI) 8-14%). Thirteen reported small bowel obstruction: prevalence 9% (95% CI 6-12%), a 58% increased risk compared with surgery alone (RR 1.58, 95% CI 1.26-1.98, n = 5 studies). Seven reported fistulas: prevalence 1% (95% CI 1-2%). Thirteen reported genitourinary complications: prevalence 4% (95% CI 1-6%); RR 1.10 (95% CI 0.88-1.38, n = 3 studies) compared with surgery alone.

CONCLUSIONS

Over 10% of patients are hospitalized for long-term complications following rectal cancer radiotherapy. Serious gastrointestinal complications are commonplace; late small bowel obstruction is more common in patients having radiotherapy and surgery compared with surgery alone. Patients and clinicians need to be aware of these risks.

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 ).

Lifestyle interventions after colorectal cancer surgery using a mobile digital device: A study protocol for a randomized controlled trial

BACKGROUND

In treating colorectal cancer, surgical techniques and adjuvant treatments have advanced over the past century, but relatively less attention has been given to improve health-related quality of life (HRQOL). Recent studies report a significant association between cancer recurrence and patient lifestyle after surgery, hence emphasizing the need to assist patients to reduce this risk through appropriate lifestyle choices. The proposed study will evaluate the effects of digital interventions on lifestyle after surgery for colorectal cancer using mobile applications.

METHODS

A randomized controlled trial design was proposed. A total of 320 patients diagnosed with colorectal cancer aged between 20 and 70 years were to be enrolled and randomized in equal numbers into 4 groups (3 groups assigned to different mobile applications and a control group). Surveys that evaluate HRQOL, physical measurements, and metabolic parameters (fasting glucose, hemoglobin A1C, triglyceride, high-density lipoprotein cholesterol), and fat/muscle mass measurements by abdominal computed tomography (CT), will be conducted prior to surgery and every 6 months post-surgery for 18 months. Statistical analysis will be used to compare the outcomes between groups.

DISCUSSION

Results from this study could provide evidence that easily accessible mobile applications can influence patient lifestyles. Results showing minimal effects of such applications could also be constructive for improving healthcare-related applications.

Population pharmacokinetic analyses of regorafenib and capecitabine in patients with locally advanced rectal cancer (SAKK 41/16 RECAP)

AIM

Locally advanced rectal cancer (LARC) is an area of unmet medical need with one third of patients dying from their disease. With response to neoadjuvant chemo-radiotherapy being a major prognostic factor, trial SAKK 41/16 assessed potential benefits of adding regorafenib to capecitabine-amplified neoadjuvant radiotherapy in LARC patients.

METHODS

Patients received regorafenib at three dose levels (40/80/120 mg once daily) combined with capecitabine 825 mg/m² bidaily and local radiotherapy. We developed population pharmacokinetic models from plasma concentrations of capecitabine and its metabolites 5'-deoxy-5-fluorocytidine and 5'-deoxy-5-fluorouridine as well as regorafenib and its metabolites M-2 and M-5 as implemented into SAKK 41/16 to assess potential drug-drug interactions (DDI). After establishing parent-metabolite base models, drug exposure parameters were tested as covariates within the respective models to investigate for potential DDI. Simulation analyses were conducted to quantify their impact.

RESULTS

Plasma concentrations of capecitabine, regorafenib and metabolites were characterized by one- and two compartment models and absorption was described by parallel first- and zero-order processes and transit compartments, respectively. Apparent capecitabine clearance was 286 L/h (relative standard error [RSE] 14.9%, interindividual variability [IIV] 40.1%) and was reduced by regorafenib cumulative area under the plasma-concentration curve (median reduction of 45.6%) as exponential covariate (estimate -4.10×10^-4 , RSE 17.8%). Apparent regorafenib clearance was 1.94 L/h (RSE 12.1%, IIV 38.1%). Simulation analyses revealed significantly negative associations between capecitabine clearance and regorafenib exposure.

CONCLUSIONS

This work informs the clinical development of regorafenib and capecitabine combination treatment and underlines the importance to study potential DDI with new anticancer drug combinations.

Comparison of tumor regression grade and clinical stage based on MRI image as a selection criterion for non-radical management after concurrent chemoradiotherapy in locally advanced rectal cancer: a multicenter, retrospective, cross-sectional study

PURPOSE

There has been no comparative study on the clinical value of magnetic resonance tumor regression grade (mrTRG)1-2 and ycT0-1N0 for the prediction of ypT0-1N0 after concurrent chemoradiotherapy (CCRT) for rectal cancer. We compared the diagnostic performance between mrTRG1-2 and ycT0-1N0 for predicting ypT0-1N0 as a selection criterion for non-radical management after CCRT in locally advanced rectal cancer.

METHODS

This retrospective study enrolled 291 patients from three referral hospitals between January 2018 and March 2020. The diagnostic performance of ycT0-1N0 and mrTRG1-2 for the prediction of ypT0-1N0 was compared in terms of sensitivity, specificity, positive-predictive value, negative-predictive value, and area under the curve (AUC).

RESULTS

Sixty-eight patients (23.4%) achieved ypT0-1N0. Nineteen patients (6.5%) had ycT0-1N0, and 91 patients (31.2%) had mrTRG1-2. For predicting ypT0-1N0, ycT0-1N0 had a sensitivity of 16.2% (95% confidence interval [CI]: 8.36‒27.10) and positive-predictive value of 57.9% (95% CI: 36.57‒76.63), while mrTRG1-2 had a sensitivity of 58.8% (95% CI: 46.23‒70.63) and positive-predictive value of 44.0% (95% CI: 36.46‒51.74). When predicting ypT0-1N0, mrTRG1-2 showed a higher AUC (0.680, 95% CI: 0.604‒0.756) than ycT0-1N0 (0.563, 95% CI: 0.481‒0.645) (P < 0.001).

CONCLUSION

mrTRG1-2 might be a better indicator than ycT0-1N0 for the selection of non-radical management of advanced rectal cancer post-CCRT. However, additional diagnostic tools are required for predicting ypT0-1N0 because mrTRG1-2 or yc stage on MRI has insufficient evidence for diagnosing ypT0-1N0.

Non-Operative Management of Patients with Rectal Cancer: Lessons Learnt from the OPRA Trial

Over the past decade, the management of locally advanced rectal cancer (LARC) has progressively become more complex. The introduction of total neoadjuvant treatment (TNT) has increased the rates of both clinical and pathological complete response, resulting in excellent long-term oncological outcomes. As a result, non-operative management (NOM) of LARC patients with a clinical complete response (cCR) after neoadjuvant therapy has gained acceptance as a potential treatment option in selected cases. NOM is based on replacement of surgical resection with safe and active surveillance. However, the identification of appropriate candidates for a NOM strategy without compromising oncologic safety is currently challenging due to the lack of an objective standardization. NOM should be part of the treatment plan discussion with LARC patients, considering the increasing rates of cCR, patient preference, quality of life, expectations, and the potential avoidance of surgical morbidity. The recently published OPRA trial showed that organ preservation is achievable in half of rectal cancer patients treated with TNT, and that chemoradiotherapy followed by consolidation chemotherapy may an appropriate strategy to maximize cCR rates. Ongoing trials are investigating optimal algorithms of TNT delivery to further expand the pool of patients who may benefit from NOM of LARC.

Nonoperative Management for Rectal Cancer

The treatment algorithm for locally advanced rectal cancer (LARC) has increased in complexity over the past 10 years. Nonoperative management (NOM) for rectal cancer in patients with clinical complete response (cCR) after neoadjuvant therapy has been gaining acceptance as a potential treatment option for selected LARC patients. The current challenge is to accurately select the patients with an apparent cCR, thereby correctly identifying those would-be appropriate candidates for a NOM strategy. NOM should be part of the treatment discussion of LARC, considering increasing rates of cCR, patient preference, potential quality of life gains, and the potential avoidance of surgical morbidity.

More Is Not Better When It Comes to Treating Rectal Cancer With Multimodal Chemoradiation Beyond the Standard Radiation Dose of 5040 cGy

BACKGROUND

Radiation dose schedules for neoadjuvant chemoradiation for rectal cancers differ, with the most common dose schedule using 5040 cGy in 28 fractions.

OBJECTIVES

The aim of this retrospective study was to assess the benefit of higher radiation doses beyond 5040 cGy in the context of pathological response and follow-up events.

SETTING

The database from a provincial tertiary cancer center in Canada was the source of information for this study.

PATIENTS

Included in this study were 508 consecutive patients with rectal cancer with locally advanced disease (clinical T3/T4 or N1/N2) who received neoadjuvant chemoradiation followed by surgery. Of the 508 patients, 281 received the standard radiation dose of 4500 to 5040 cGy and 227 received a dose >5040 cGy.

MAIN OUTCOME MEASURE

The postsurgical pathology, late toxicities, and follow-up outcomes were analyzed. The outcomes were evaluated in relation to the dose of radiation received.

RESULTS

Data regarding the clinical outcomes were comparable between the 4500 to 5040 cGy and >5040 cGy radiation groups with pathological complete response rates of 20.9% and 15.4% (p = 0.104); distant recurrence rates of 17.4% and 19.4% (p = 0.36); local recurrence rates of 3.2% and 3.5% (p = 0.36); and the median overall survival rates of 61 and 60.5 months (p = 0.8). No statistically significant correlation of improvement in outcomes was noted with radiation doses beyond 5040 cGy.

LIMITATIONS

This is a retrospective study.

CONCLUSION

Our study showed that dose escalation beyond the standard dose of 4500 to 5040cGy failed to achieve meaningful clinical outcomes. See Video Abstract at http://links.lww.com/DCR/B633.

MS NO ES MEJOR CUANDO SE TRATA DE TRATAR EL CNCER DE RECTO CON QUIMIORRADIACIN MULTIMODAL MS ALL DE LA DOSIS DE RADIACIN ESTNDAR DE CGY

ANTECEDENTES:En neoadyuvancia de cáncer rectal es posible encontrar muchas variaciones, en radioterapia la dosis más común que usa 5040 cGy en 28 fracciones.OBJETIVOS:El objetivo de este estudio retrospectivo fue evaluar el beneficio de dosis de radiación más altas más allá de 5040cGy en el contexto de la respuesta patológica y en su seguimiento.AJUSTE:Base de datos de un centro de cáncer terciario provincial en Canadá.PACIENTES:Se incluyeron en este estudio quinientos ocho pacientes consecutivos con cáncer de recto y enfermedad localmente avanzada (clínica T3 / T4 o N1 / N2) que recibieron quimiorradiación neoadyuvante seguida de cirugía. De los 508 pacientes, 281 recibieron la dosis de radiación estándar de 4500-5040 cGy y 227 recibieron una dosis > 5040 cGy.PRINCIPAL MEDIDA DE RESULTADO:Se analizo evolucion posquirúrgica, toxicidad tardía y seguimiento. Los resultados se evaluaron en relación con la dosis de radiación recibida.RESULTADOS:Los datos con respecto a los resultados clínicos fueron comparables entre los grupos de radiación de 4500-5040 cGy y> 5040 cGy con tasas de respuesta patológica completa de 20,9% y 15,4% respectivamente (p = 0,104); tasas de recurrencia a distancia de 17,4% y 19,4%, respectivamente (p = 0,36); tasas de recurrencia local de 3,2% y 3,5%, respectivamente (p = 0,36); y la mediana de las tasas de supervivencia global de 61 y 60,5 meses, respectivamente (p = 0,8). No se observó una correlación estadísticamente significativa de mejoría en los resultados con dosis de radiación superiores a 5040 cGy.LIMITACIONES:Este es un estudio retrospectivo.CONCLUSIONES:Nuestro estudio mostró que el aumento de la dosis más allá de la dosis estándar de 4500-5040cGy no logró resultados clínicos significativos. Consulte Video Resumen en http://links.lww.com/DCR/B633. (Traducción-Dr. Gunther Bocic).

Neoadjuvant Therapy for Rectal Cancer

The treatment of locally advanced rectal cancer is challenging and requires a multidisciplinary approach. Neoadjuvant treatment has improved local control by the combination of radiotherapy, surgery, and chemotherapy. However, neoadjuvant treatment has not yet been shown to improve overall survival and is associated with toxicities and late sequelae that impair the quality of life of patients. Currently, different types of neoadjuvant strategies have raised the question about which one is the optimal strategy for rectal cancer treatment. In this article, we explore the different neoadjuvant treatment regimens currently available, their associated benefits and toxicities, and novel approaches in this area.

Arrabidaea chica chloroform extract modulates estrogen and androgen receptors on luminal breast cancer cells

BACKGROUND

Breast Cancer (BC) is the most common cancer in women worldwide and, although 70% of patients are responsive to selective Estrogen Receptor (ER) modulators such as Tamoxifen (Tam), patients' survival is comprised by resistance to endocrine therapy. Brazilian flora, especially the Amazon biome, is one of the richest global sources of native species with potentially bioactive compounds. Arrabidaea chica is a plant native to the Amazon that has been used in the treatment of different diseases. However, its action on BC remains unclear.

METHODS

Herein the biological effects of the chloroform extract of A. chica (CEAC) were evaluated on BC cells and in in vivo model. After confirmation of CEAC antioxidant capacity, cells were treated with CEAC and Tam, alone and with CEAC+Tam. The cell viability was evaluated by MTT and hormone receptor transcripts levels were assessed (ESR1, ESR2 and AR). Finally, anticarcinogenicity of CEAC was recorded in Drosophila melanogaster through Epithelial Tumor Test (ETT).

RESULTS

The study confirmed the antioxidant activity of CEAC. CEAC was selective for MCF-7, downregulating ESR2 and AR transcripts and upregulating ESR2 expression. The modulatory effects of CEAC on ERs did not differ between cells treated with Tam and with CEAC+Tam. Interestingly, previous treatment with CEAC, followed by treatment with Tam promoted a significant decrease in cell viability. The extract also presented anticarcinogenic effect in in vivo assay.

CONCLUSION

The bioassays on breast tumor cells demonstrated the antiproliferative activity of the extract, which modulated the expression of hormone receptors and sensitized luminal tumor cells to Tam. These results suggest that CEAC could be a complementary treatment for BC.

Effects of Neoadjuvant Radiotherapy on Postoperative Complications in Rectal Cancer: A Meta-Analysis

Objective

Neoadjuvant radiotherapy (nRT) is an important treatment approach for rectal cancer. The relationship, however, between nRT and postoperative complications is still controversial. Here, we conducted a meta-analysis to evaluate such concerns.

Methods

The electronic literature from 1983 to 2021 was searched in PubMed, Embase, and Web of Science. Postoperative complications after nRT were included in the meta-analysis. The pooled odds ratio (OR) was calculated by the random-effects model. Statistical analysis was conducted by Review Manager 5.3 and STATA 14.

Results

A total of 23,723 patients from 49 studies were included in the meta-analysis. The pooled results showed that nRT increased the risk of anastomotic leakage (AL) compared to upfront surgery (OR = 1.23; 95% CI, 1.07-1.41; p=0.004). Subgroup analysis suggested that both long-course (OR = 1.20, 95% CI 1.03-1.40; p=0.02) and short-course radiotherapy (OR = 1.25, 95% CI, 1.02-1.53; p=0.04) increased the incidence of AL. In addition, nRT was the main risk factor for wound infection and pelvic abscess. The pooled data in randomized controlled trials, however, indicated that nRT was not associated with AL (OR = 1.01; 95% CI 0.82-1.26; p=0.91).

Conclusions

nRT may increase the risk of AL, wound infection, and pelvic abscess compared to upfront surgery among patients with rectal cancer.

Rectal cancer radiotherapy

We present the updated recommendations of the French society of oncological radiotherapy for rectal cancer radiotherapy. The standard treatment for locally advanced rectal cancer consists in chemoradiotherapy followed by radical surgery with total mesorectal resection and adjuvant chemotherapy according to nodal status. Although this strategy efficiently reduced local recurrences rates below 5% in expert centres, functional sequelae could not be avoided resulting in 20 to 30% morbidity rates. The early introduction of neoadjuvant chemotherapy has proven beneficial in recent trials, in terms of recurrence free and metastasis free survivals. Complete pathological responses were obtained in 15% of tumours treated by chemoradiation, even reaching up to 30% of tumours when neoadjuvant chemotherapy is associated to chemoradiotherapy. These good results question the relevance of systematic radical surgery in good responders. Personalized therapeutic strategies are now possible by improved imaging modalities with circumferential margin assessed by magnetic resonance imaging, by intensity modulated radiotherapy and by refining surgical techniques, and contribute to morbidity reduction. Keeping the same objectives, ongoing trials are now evaluating therapeutic de-escalation strategies, in particular rectal preservation for good responders after neoadjuvant treatment, or radiotherapy omission in selected cases (Greccar 12, Opera, Norad).

Survival analysis and prognostic factors of palliative radiotherapy in patients with metastatic colorectal cancer: a propensity score analysis

Background

Radiation therapy (RT) is known to have beneficial effects on the palliative treatment of patients with advanced cancer. However, valid data on this treatment method are limited, especially for patients with metastatic colorectal cancer (mCRC). This study aimed to identify prognostic factors and investigate the outcomes of mCRC patients who received palliative RT.

Methods

A total of 488 mCRC patients who underwent systemic therapy with or without palliative RT between 2014 and 2019 were included in the study. Of the 488 patients, 155 received systemic treatment combined with palliative RT (RT group), while 333 were only administered systemic treatment (non-RT group). Propensity score matching (PSM) was conducted to eliminate possible bias, and overall survival (OS) was calculated using the Kaplan-Meier (KM) method. A log-rank test was used to compare the survival outcomes of each group, and a multivariate analysis was conducted using a Cox proportional hazards model.

Results

The RT group had a higher OS than that of the non-RT group (P=0.001). After PSM, the median OS of the RT group was 50.8 months, and for the non-RT group it was 32.2 months (P=0.003). Subgroup analysis revealed that RT had a better effect on the OS of patients who had synchronous metastasis, or who didn't receive targeted therapy or local treatment (including surgery, ablation, and intervention). Multivariate analysis of the whole cohort showed that palliative RT was associated with improved OS. Moreover, multivariate analysis of the RT group showed that systemic therapy before RT, and the site of RT was in the liver and lung, were independent prognostic factors affecting survival time.

Conclusions

We demonstrated that systemic treatment followed by palliative RT led to a better OS for mCRC patients. This combination method can therefore be seen as a suitable treatment approach for patients with mCRC.

Postoperative Chemoradiotherapy With Capecitabine and Oxaliplatin vs Capecitabine for Stage II to III Rectal Cancer: A Randomized Clinical Trial

IMPORTANCE

Several studies have explored the efficacy and toxic effects of concurrent 5-fluorouracil (5-FU)- or capecitabine-based chemoradiotherapy (CRT) with or without oxaliplatin in the neoadjuvant setting. Addition of oxaliplatin to 5-FU or capecitabine elicited similar outcomes but with significantly increased toxic effects; however, there is a need for randomized clinical trials comparing 2 CRT regimens for patients receiving CRT in the adjuvant setting.

OBJECTIVE

To explore the efficacy and toxic effects of oxaliplatin combined with postoperative concurrent capecitabine and radiotherapy (RT) for pathological stage II and III rectal cancer.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter randomized clinical trial enrolled patients from 7 centers in China between April 1, 2008, and December 30, 2015. Patients with pathologically confirmed stage II and III rectal cancer were randomized (1:1) to receive concurrent CRT with capecitabine or capecitabine plus oxaliplatin. Analysis was conducted from December 31, 2019, to March 15, 2020.

INTERVENTIONS

RT comprised 45 to 50 Gy in 25 fractions of 1.8 to 2.0 Gy over 5 weeks. In the capecitabine with RT group, concurrent chemotherapy included 2 cycles of capecitabine (1600 mg/m2) on days 1 to 14 and 22 to 35. The capecitabine and oxaliplatin with RT group received identical postoperative RT to that in the capecitabine with RT group combined with capecitabine (1300 mg/m2) on days 1 to 14 and 22 to 35 and a 2-hour infusion of oxaliplatin (60 mg/m2) on weeks 1, 2, 4, and 5. Patients in both groups received adjuvant chemotherapy (capecitabine or fluorouracil and oxaliplatin) after CRT.

MAIN OUTCOMES AND MEASURES

The primary end point was 3-year disease-free survival (DFS).

RESULTS

A total of 589 patients (median [IQR] age, 55 [47-52] years; 375 [63.7%] men and 214 [36.3%] women) were enrolled, including 294 patients randomized to the capecitabine with RT group and 295 patients randomized to the capecitabine and oxaliplatin with RT group. Median (IQR) follow-up was 68 (45-96) months. Most patients had stage III disease (574 patients [75.9%]). Three-year DFS was 76.3% for the capecitabine with RT group and 74.1% for the capecitabine and oxaliplatin with RT group, and 5-year DFS was 72.0% for the capecitabine with RT group and 71.1% for the capecitabine and oxaliplatin with RT group (hazard ratio [HR], 1.07; 95% CI, 0.79-1.44; P = .68). There was no significant difference between groups in overall survival (HR, 0.93; 95% CI, 0.64-1.34; P = .70) or local recurrence (HR, 0.61; 95% CI, 0.31-1.22; P = .16). More grade 3 and 4 acute toxic effects were observed in the capecitabine and oxaliplatin with RT group than in the capecitabine with RT group (114 patients [38.6%] vs 84 patients [28.6%]; P = .01).

CONCLUSIONS AND RELEVANCE

This randomized clinical trial found that addition of oxaliplatin to capecitabine-based postoperative CRT did not improve the efficacy of treatment but increased the risk of severe acute toxic effects. This finding highlights the basic role of postoperative capecitabine with RT for patients with locally advanced rectal cancer.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00714077.

The Correlation Between Survival Benefit of Preoperative Radiotherapy and Pretreatment Carcinoembryonic Antigen Level in Locally Advanced Rectal Cancer

Background

Preoperative radiotherapy followed by radical surgery is the standard treatment for locally advanced rectal cancer; however, its long-term survival benefit remains controversial. This study aimed to determine the relationship between pretreatment carcinoembryonic antigen (CEA) levels and the long-term prognosis of preoperative radiotherapy in locally advanced rectal cancer (LARC) patients.

Methods

Data of LARC patients who underwent surgery between 2011 and 2015 were identified from the Surveillance, Epidemiology, and End Results (SEER) database, and patients were accordingly divided into surgery (S) group and radiotherapy followed by surgery (RT+S) group. The primary outcomes were cancer-specific survival (CSS) and cancer-specific mortality (CSM). CSS was evaluated using Kaplan-Meier analysis, while CSM was evaluated using a competitive risk model. Subgroup analysis was also conducted, which was stratified by pretreatment CEA levels.

Results

A total of 2,760 patients were eligible for this study, including 350 (12.7%) patients in the S group and 2,410 (87.3%) in the RT+S group. There were no significant differences in the CSS and CSM rates at 1, 3, and 4 years between the S and RT+S groups before and after PSM (all p > 0.05). Pretreatment CEA levels were independently associated with CSS and CSM after adjusting for age, sex, stage, pathological factors, and treatment factors (all p < 0.05). Subgroup analysis showed that preoperative radiotherapy would benefit patients with elevated CEA in terms of CSS and CSM (both p < 0.05) but not those patients with normal CEA (both p > 0.05). Further analysis showed that preoperative radiotherapy was an independent protective factor for CSS and CSM in patients with elevated CEA levels (both p < 0.05).

Conclusions

Pretreatment CEA level may be considered a potential biomarker to screen LACR patients who would benefit from preoperative radiotherapy in terms of long-term prognosis.

Preoperative versus postoperative chemoradiotherapy for locally advanced rectal cancer: Outcomes of survival, toxicity, sphincter preserving and prognostic factors

BACKGROUND

This study aimed to compare preoperative chemoradiotherapy (CRT) with postoperative CRT regarding survival, local control, disease control, sphincter preservation, toxicity and also prognostic factors for the treatment of locally advanced rectal cancer.

METHODS

Records of 140 patients with locally advanced rectal cancer who received preoperative or postoperative CRT were analyzed retrospectively. We compared the treatment groups (preoperative vs postoperative) according to baseline characteristics (demographic and rectal cancer disease characteristics), and also carried out the survival analyses.

RESULTS

From January 2010 to December 2019, 140 patients were included in the analysis, 65 received preoperative treatment and 75 postoperative treatment. There was no difference in survival, recurrence or distant metastasis rate in both treatment groups. The ratios of the failure to complete adjuvant chemotherapy (32% vs 4.6%) and acute grade 3-4 toxicity (32% vs 6.2%) were higher in the postoperative group (p < 0.001). In lower located tumors (≤5 cm from anal verge) the ratio of the sphincter preserving in the preoperative group was 60.7% (n = 17/28), and was 16.6% (n = 3/18) in the postoperative group (Yates χ2 = 5.829, p = 0.005).

CONCLUSION

This study showed no difference in recurrence and survival rate. Preoperative CRT is the preferred treatment for patients with locally advanced rectal cancer, given that it is associated with a superior overall treatment compliance rate, reduced toxicity, and an increased rate of sphincter preservation in low-lying tumors, but not for overall survival.

A multicenter, propensity score-matched cohort study about short-term and long-term outcomes after laparoscopic versus open surgery for locally advanced rectal cancer

PURPOSE

This study evaluated the results of laparoscopic surgery (LAP) compared to open surgery (OP) for locally advanced mid-to-lower rectal cancer.

METHODS

From February 2008 to December 2014, we collected patient data with clinical stage II/III mid-to-lower rectal cancer who underwent resection with LAP or OP at 13 institutions associated with the Yokohama Clinical Oncology Group (YCOG). The short-term outcomes and long-term prognoses associated with LAP and OP were analyzed after adjusting for the patients' backgrounds using propensity score matching.

RESULTS

Among 1091 eligible cases, a propensity score matching with six covariates-age, sex, body mass index, American Society of Anesthesiologists physical status category, tumor location, and clinical stage-extracted 237 cases each for the LAP and OP groups, respectively. After matching, there were no differences in background factors between the two groups except for the presence or absence of preoperative treatment. Operative time was significantly longer in the LAP group than that in the OP group (p < 0.001), while the amount of bleeding and the length of postoperative hospital stay were significantly lower in the LAP group than that in the OP group (p < 0.001 and p = 0.001, respectively). There were no significant differences between groups in the incidence of postoperative complications. The 3-year overall survival and relapse-free survival rates were 90.5% and 88.6% and 78.3% and 71.6% in the LAP and OP groups, respectively, which did not differ significantly.

CONCLUSIONS

The short-term outcomes and long-term prognoses of LAP in this cohort study indicated that LAP could be a therapeutic option for locally advanced rectal cancer.

TRIAL REGISTRATION

UMIN000040406.

Meta-analysis of neoadjuvant chemotherapy versus neoadjuvant chemoradiotherapy for locally advanced rectal cancer

Background and purpose

With the advent of more intensive chemotherapy regimens, neoadjuvant chemoradiotherapy (NACRT) for patients with locally advanced rectal cancer (LARC) has always been questioned due to its inevitable radiation toxicity. Hence, we conducted a meta-analysis to compare the clinical efficacy of neoadjuvant chemotherapy (NAC) and NACRT.

Materials and methods

Eligible studies were searched using PubMed, MEDLINE, Embase, the Cochrane Library, and Web of Science up to 31 July 2020, comparing the clinical efficacy of NAC versus NACRT for LARC. Short- and long-term outcomes were determined using the odds ratio (OR) with 95% confidence interval (CI).

Results

Six studies with 12,812 patients were eligible for this meta-analysis, including 677 patients in the NAC group and 12,135 patients in the NACRT group. There were no significant differences between the two groups in terms of pathological complete response rate (OR=0.62, 95%CI=0.27~1.41), N down-staging rate (OR=1.20, 95%CI=0.25~5.79), R0 resection rate (OR=1.24, 95%CI=0.78~1.98), and local relapse rate (OR=1.12, 95%CI=0.58~2.14). The pooled OR for the total response rate and T down-staging were in favor of NACRT (OR=0.41, 95%CI=0.22~0.76 versus OR=0.67 95%CI=0.52~0.87). However, the pooled OR for the sphincter preservation rate favored NAC compared with NACRT (OR=1.87, 95%CI=1.24~2.81). Moreover, NAC was found to be superior to NACRT in terms of distant metastasis (14.3% vs. 20.4%), but the difference was not significant (OR=0.84, 95%CI=0.31~2.27).

Conclusion

We concluded that NAC was superior to NACRT in terms of the sphincter preservation rate, and non-inferior to NACRT in terms of pCR, N down-staging, R0 resection, local relapse, and distant metastasis. However, the conclusion warrants further validation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02251-0.

MRI-defined high-risk rectal cancer patients: outcome comparison between neoadjuvant chemoradiotherapy plus TME and TME plus adjuvant chemotherapy or TME alone

OBJECTIVE

The goal of this study was to investigate whether neoadjuvant chemoradiotherapy (NCRT) plus total mesorectal excision (TME) would improve the outcome of patients with MRI-defined high-risk rectal cancer compared with TME plus adjuvant chemotherapy (ACT) or TME alone.

METHODS

We retrospectively enrolled 362 patients with MRI-defined high-risk rectal cancer who were treated with NCRT plus TME, TME plus ACT, or TME alone between January 2008 and August 2018. Cases with a high-risk tumor stage, positive extramural venous invasion, or mesorectal fascia involvement on baseline MRI were considered cases of high-risk rectal cancer. We matched patients treated with NCRT plus TME to patients treated with TME plus ACT and to those treated with TME alone. Kaplan-Meier curves were used to compare local recurrence (LR), disease-free survival (DFS), and overall survival (OS) rates.

RESULTS

The cumulative 3 year LR rate in the matched NCRT plus TME group was more favorable than in the TME plus ACT group (0% vs 5.1%; p = 0.037; n = 98) and in the TME alone group (0% vs 11.5%; p = 0.016; n = 61). Patients who received NCRT plus TME demonstrated better cumulative 3 year DFS rates than patients treated with TME plus ACT (85.7% vs 65.3%; p = 0.009) or with TME alone (86.9% vs 68.9%; p = 0.046). No difference in OS was observed among the groups.

CONCLUSION

NCRT may improve DFS and LR rates in patients with MRI-defined high-risk rectal cancer when compared with TME plus ACT or TME alone.

ADVANCES IN KNOWLEDGE

This study illustrated the specific benefit of NCRT on the outcome measures of MRI-defined high-risk rectal cancer compared with TME plus ACT or TME alone, which was not clearly clarified in previous studies enrolling all patients with Stage II/III rectal cancer.

Radiation Therapy for Rectal Cancer: Executive Summary of an ASTRO Clinical Practice Guideline

PURPOSE

This guideline reviews the evidence and provides recommendations for the indications and appropriate technique and dose of neoadjuvant radiation therapy (RT) in the treatment of localized rectal cancer.

METHODS

The American Society for Radiation Oncology convened a task force to address 4 key questions focused on the use of RT in preoperative management of operable rectal cancer. These questions included the indications for neoadjuvant RT, identification of appropriate neoadjuvant regimens, indications for consideration of a nonoperative or local excision approach after chemoradiation, and appropriate treatment volumes and techniques. Recommendations were based on a systematic literature review and created using a predefined consensus-building methodology and system for grading evidence quality and recommendation strength.

RESULTS

Neoadjuvant RT is recommended for patients with stage II-III rectal cancer, with either conventional fractionation with concurrent 5-FU or capecitabine or short-course RT. RT should be performed preoperatively rather than postoperatively. Omission of preoperative RT is conditionally recommended in selected patients with lower risk of locoregional recurrence. Addition of chemotherapy before or after chemoradiation or after short-course RT is conditionally recommended. Nonoperative management is conditionally recommended if a clinical complete response is achieved after neoadjuvant treatment in selected patients. Inclusion of the rectum and mesorectal, presacral, internal iliac, and obturator nodes in the clinical treatment volume is recommended. In addition, inclusion of external iliac nodes is conditionally recommended in patients with tumors invading an anterior organ or structure, and inclusion of inguinal and external iliac nodes is conditionally recommended in patients with tumors involving the anal canal.

CONCLUSIONS

Based on currently published data, the American Society for Radiation Oncology task force has proposed evidence-based recommendations regarding the use of RT for rectal cancer. Future studies will look to further personalize treatment recommendations to optimize treatment outcomes and quality of life.

Sphincter-saving surgery for ultra-low rectal carcinoma initially indicated for abdominoperineal resection: Is it safe on a long-term follow-up?

BACKGROUND

Rate of abdominoperineal resection (APR) varies from countries and surgeons. Surgical impact of preoperative treatment for ultra-low rectal carcinoma (ULRC) initially indicated for APR is debated. We report the 10-year oncological results from a prospective controlled trial (GRECCAR 1) which evaluate the sphincter saving surgery (SSR).

METHODS

ULRC indicated for APR were included (n = 207). Randomization was between high-dose radiation (HDR, 45 + 18 Gy) and radiochemotherapy (RCT, 45 Gy + 5FU infusion). Surgical decision was based on tumour volume regression at surgery. SSR technique was standardized as mucosectomy (M) or partial (PISR)/complete (CISR) intersphincteric resection.

RESULTS

Overall SSR rate was 85% (72% ISR), postoperative morbidity 27%, with no mortality. There were no significant differences between the HDR and RCT groups: 10-year overall survival (OS10) 70.1% versus 69.4%, respectively, 10.2% local recurrence (9.2%/14.5%) and 27.6% metastases (32.4%/27.7%). OS and disease-free survival were significantly longer for SSR (72.2% and 60.1%, respectively) versus APR (54.7% and 38.3%). No difference in OS10 between surgical approaches (M 78.9%, PISR 75.5%, CISR 65.5%) or tumour location (low 64.8%, ultralow 76.7%).

CONCLUSION

GRECCAR 1 demonstrates the feasibility of safely changing an initial APR indication into an SSR procedure according to the preoperative treatment tumour response. Long-term oncologic follow-up validates this attitude.

Phase II Trial of Neoadjuvant Bevacizumab with Modified FOLFOX7 in Patients with Stage II and III Rectal Cancer

LESSONS LEARNED

Neoadjuvant bevacizumab with modified FOLFOX7 without radiation failed to meet the goal of pathological complete response rate; however, the low number of recurrence and disease-free survival in this population, with predominantly stage III, is encouraging and worth further exploration. The racial distribution of the patient population, as well as a wait time of more than 4 weeks after last chemotherapy, may have contributed to the findings.

BACKGROUND

Combination chemotherapy in lieu of radiation in rectal adenocarcinoma is under exploration in multiple trials. We evaluated the efficacy of neoadjuvant FOLFOX + bevacizumab in patients (pts) with clinical stage II and III disease.

METHODS

Pts received six cycles of bevacizumab (5 mg/kg) and modified FOLFOX7 (oxaliplatin 85 mg/m² , leucovorin 20 mg/m² , and fluorouracil [5-FU] 2,400 mg/m² ). Surgical resection was performed 6-8 weeks after completion of treatment and upon confirmation of nonmetastatic disease. We employed a Simon two-stage design and required three pathological complete responses (pCR) in the first 18 pts, with a prespecified pCR rate of 25% before moving to the next stage.

RESULTS

Seventeen pts enrolled; 65% at stage III. Median age was 57 (35-79), 65% were male, 47% were Hispanic, 35% were white, and 18% were Asian. All pts but one completed six cycles of therapy. One pCR was observed (6%), and 11 of 17 (65%) pts had pathological downstaging. One patient experienced systemic recurrence and remains on treatment. Probability of disease-free survival (DFS) at 5 years is 0.94 (SE, 0.06).

CONCLUSION

The study failed to meet the required three pCRs in the first 18 pts. The DFS in this population is encouraging and supports the hypothesis that select pts with rectal cancer may be spared from radiation.

Prognostic Impact of Extranodal Extension in Rectal Cancer Patients Undergoing Radical Resection After Preoperative Chemoradiotherapy

BACKGROUND

Extranodal extension (ENE) of nodal metastasis has emerged as an important prognostic factor in many malignancies, including rectal cancer. However, its significance in patients with rectal cancer receiving preoperative chemoradiotherapy (PCRT) has not been extensively investigated. We therefore assessed ENE and its prognostic impact in a large series of consecutive rectal cancer patients with lymph node metastasis after PCRT and curative resection.

PATIENTS AND METHODS

Between January 2000 and December 2014, a total of 1925 patients with rectal cancer underwent surgical resection after PCRT. Medical records of 469 patients with pathologic node positivity were retrospectively reviewed.

RESULTS

Of the 469 patients, 118 (25.2%) presented with ENE. ENE was observed more frequently in those with advanced tumor stage (higher ypT, ypN, and ypStage), lymphovascular invasion, and perineural invasion. Five-year disease-free survival rate was lower in patients with ENE-positive tumors than those with ENE-negative tumors (36.1% vs. 52.3%, P = .003). Similarly, 5-year overall survival rate was lower in patients with ENE-positive tumors than those with ENE-negative tumors (60.2% vs. 70.6%, P < .001). Multivariate analysis revealed that the presence of ENE was an independent poor prognostic factor for disease-free survival (hazard ratio = 1.412; 95% confidence interval, 1.074-1.857; P = .013) and overall survival (hazard ratio = 1.531; 95% confidence interval 1.149-2.039; P = .004).

CONCLUSION

The presence of ENE in patients with rectal cancer undergoing PCRT is a negative prognostic factor, reflecting poor survival outcome.

A bibliometric analysis of 23,492 publications on rectal cancer by machine learning: basic medical research is needed

BACKGROUND AND AIMS

The aim of this study was to analyse the landscape of publications on rectal cancer (RC) over the past 25 years by machine learning and semantic analysis.

METHODS

Publications indexed in PubMed under the Medical Subject Headings (MeSH) term 'Rectal Neoplasms' from 1994 to 2018 were downloaded in September 2019. R and Python were used to extract publication date, MeSH terms and abstract from the metadata of each publication for bibliometric assessment. Latent Dirichlet allocation was applied to analyse the text from the articles' abstracts to identify more specific research topics. Louvain algorithm was used to establish a topic network resulting in identifying the relationship between the topics.

RESULTS

A total of 23,492 papers published were identified and analysed in this study. The changes of research focus were analysed by the changing of MeSH terms. Studied contents extracted from the publications were divided into five areas, including surgical intervention, radiotherapy and chemotherapy intervention, clinical case management, epidemiology and cancer risk as well as prognosis studies.

CONCLUSIONS

The number of publications indexed on RC has expanded rapidly over the past 25 years. Studies on RC have mainly focused on five areas. However, studies on basic research, postoperative quality of life and cost-effective research were relatively lacking. It is predicted that basic research, inflammation and some other research fields might become the potential hotspots in the future.

Neoadjuvant Radiotherapy Dose Escalation in Locally Advanced Rectal Cancer: a Systematic Review and Meta-analysis of Modern Treatment Approaches and Outcomes

AIMS

Improving pathological complete response (pCR) rates after neoadjuvant chemoradiotherapy for locally advanced rectal cancer may facilitate surgery-sparing treatment paradigms. Radiotherapy boost has been linked to higher rates of pCR; however, outcomes in moderately escalated inverse-planning studies have not been systematically evaluated. We therefore carried out a systematic review and meta-analysis of radiation dose-escalation studies in the context of neoadjuvant therapy for locally advanced rectal cancer.

MATERIALS AND METHODS

A systematic search of Pubmed, EMBASE and Cochrane databases for synonyms of 'rectal cancer', 'radiotherapy' and 'boost' was carried out. Studies were screened for radiotherapy prescription >54 Gy. Prespecified quality assessment was carried out for meta-analysis inclusion suitability. Pooled estimates of pCR, acute toxicity (grade ≥3) and R0 resection rates were determined with random-effects restricted maximum-likelihood estimation. Heterogeneity was assessed with Higgins I² and Cochran Q statistic. Subset analysis examined outcomes in modern inverse-planning studies. Meta-regression with permutation correction was carried out for each outcome against radiation dose, radiotherapy technique, boost technique, chemotherapy intensification and other patient- and treatment-related cofactors.

RESULTS

Forty-nine primary and three follow-up publications were included in the systematic review. Pooled estimates of pCR, toxicity and R0 resection across 37 eligible publications (n = 1817 patients) were 24.1% (95% confidence interval 21.2-27.4%), 11.2% (95% confidence interval 7.2-17.0%) and 90.7% (95% confidence interval 87.9-93.8%). Within inverse-planning studies (17 publications, n = 959 patients), these rates were 25.7% (95% confidence interval 21.0-31.1%), 9.8% (95% confidence interval 4.6-19.7%) and 95.3% (95% confidence interval 91.6-97.4%). Regression analysis did not identify any significant predictor of pCR (P > 0.05).

CONCLUSIONS

Radiotherapy dose escalation above 54 Gy is associated with high rates of pCR and does not seem to increase the risk of acute grade ≥3 toxicity events. pCR rates approaching 25% may be achievable utilising moderate escalation (54-60 Gy) with modern inverse-planning techniques; however, a clear dose-response relationship was not identified in regression analysis and additional evidence is awaited given the prevalence of heterogenous single-arm studies to date.

Impact of preoperative chemoradiotherapy using concurrent S-1 and CPT-11 on long-term clinical outcomes in locally advanced rectal cancer

BACKGROUND

Preoperative chemoradiotherapy regimens using a second drug for locally advanced rectal cancer are still under clinical investigation.

AIM

To investigate the clinical outcomes of patients with locally advanced rectal cancer treated with preoperative chemoradiotherapy using tegafur/gimeracil/oteracil (S-1) plus irinotecan (CPT-11).

METHODS

This was a single-center retrospective study of 82 patients who underwent radical surgery for rectal cancer after chemoradiotherapy with S-1 (80 mg/m²/d), CPT-11 (60 mg/m²/d), and radiation (total 45 Gy) between 2009 and 2016. The median follow-up was 51 mo (range: 17–116 mo).

RESULTS

Twenty-nine patients (35.4%) had T3 or T4 rectal cancer with mesorectal fascia invasion, 36 (43.9%) had extramural vascular invasion, 24 (29.8%) had N2 rectal cancer and eight (9.8%) had lateral lymph node swelling. The relative dose intensity was 90.1% for S-1 and 92.9% for CPT-11. Seventy-nine patients (96.3%) underwent R0 resection. With regard to pathological response, 13 patients (15.9%) had a pathological complete response and 52 (63.4%) a good response (tumor regression grade 2/3). The 5-year local recurrence-free survival, relapse-free survival and overall survival rates were 90.1%, 72.5% and 91.3%, respectively. We analyzed the risk factors for local recurrence-free survival by Cox regression analysis and none were detected. Previously described risk factors such as T4 stage, mesorectal fascia invasion or lateral lymph node swelling were not detected as negative factors for local recurrence-free survival.

CONCLUSION

We demonstrated good compliance and favorable tumor regression in patients with locally advanced rectal cancer treated with preoperative S-1 and CPT-11.

Neoadjuvant radiotherapy improves overall survival for T3/4N+M0 rectal cancer patients: a population-based study of 20300 patients

Background

Neoadjuvant radiotherapy (RT) has been shown to improve local control; however, whether it can improve overall survival (OS) in locally advanced rectal cancer (LARC) patients remains controversial. We therefore aimed to examine the benefits of surgery alone, neoadjuvant radiotherapy (RT), adjuvant RT, and surgery plus chemotherapy in stage II (T3/4N0M0) and III (any T and N + M0) on the OS of rectal cancer patients.

Methods

Date from the Surveillance, Epidemiology, and End Results (SEER) database diagnosed between 2004 and 2016 were used. Kaplan-Meier analyses were used to compare patient prognoses across different treatment modalities. Cox hazard regression analysis were used to identify independent predictors of OS.

Results

For stage T3/4N0M0 patients, neoadjuvant RT, adjuvant RT, and surgery plus chemotherapy resulted in similar OS (all p > 0.05; mean survival, 115.89 months (M), 111.97 M, and 117.22 M, respectively), with better OS observed in these patients than in patients who underwent surgery alone (all p < 0.001, mean survival, 88.96 M). For stage T1/2N + M0 patients, neoadjuvant RT, adjuvant RT, and surgery plus chemotherapy resulted in similar OS (all p > 0.05; mean survival, 121.50 M, 124.25 M, and 121.20 M, respectively), with better OS observed in these patients than in patients who underwent surgery alone (all p < 0.001, mean survival 83.81 M). For stage T3/4N + M0 patients, neoadjuvant RT (HR = 0.436; 95% CI, 0.396~0.478; p < 0.001) resulted in significantly longer OS than adjuvant RT and surgery plus chemotherapy (mean survival, 104.47 M, 93.94 M, and 93.62 M, respectively), with better OS observed in these patients than in patients who underwent surgery alone (all p < 0.001, mean survival 54.87 M). Older age (> 60 years), black race, unmarried status, high tumour grade, and tumour size > 5 cm were all associated with a poor prognosis (all p < 0.05).

Conclusions

Neoadjuvant RT, adjuvant RT, and surgery plus chemotherapy results in better OS than surgery alone in LARC patients. Neoadjuvant RT has the potential to be highly recommended over adjuvant RT and surgery plus chemotherapy for T3/4N + M0 patients; however, it showed no OS advantage over adjuvant RT or surgery plus chemotherapy for T3/4N0M0 and T1/2N + M0 patients.

Neoadjuvant chemoradiotherapy might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer: A retrospective single-institution study with propensity score-matched comparative analysis

BACKGROUND

Neoadjuvant chemoradiotherapy (NACRT) and total mesorectal excision (TME) are standard treatments of stage II/III locally advanced rectal cancer (LARC), currently. Here, we evaluated the oncological outcomes in LARC patients treated with NACRT compared to TME alone, and determined whether tumor regression grade (TRG) and pathologic response after NACRT was related to prognosis.

METHODS

This is a retrospective comparison of 358 LARC patients treated with either TME alone (non-NACRT group, n = 173) or NACRT plus TME (NACRT group, n = 185) during 2003-2013. Perioperative and oncologic outcomes, like overall survival (OS), disease-free survival (DFS) and recurrence were compared using 1:1 propensity score matching analysis.

RESULTS

A total of 133 patients were matched for the analysis. After a median follow-up of 45 months (8-97 months), the 5-year OS (NACRT vs non-NACRT: 75.42% vs 72.76%; P = 0.594) and 5-year DFS (NACRT vs non-NACRT: 74.25% vs 70.13%; P = 0.224) were comparable between NACRT and non-NACRT, whereas the 5-year DFS rate was higher in the NACRT group when only stage IIIb/IIIc patients were considered (NACRT vs. non-NACRT: 74.79% vs. 62.29%; P = 0.056). In the NACRT group of 185 patients, those with pCR/stage I (vs stage II/stage III disease) or TRG3/TRG4 disease (vs TRG0/TRG1/TRG2) had significantly better prognosis.

CONCLUSION

NACRT might provide survival benefit in patients with stage IIIb/IIIc locally advanced rectal cancer.

Cost-effectiveness analysis of long-course oxaliplatin and bolus of fluorouracil based preoperative chemoradiotherapy vs. 5x5Gy radiation plus FOLFOX4 for locally advanced resectable rectal cancer

PURPOSE

To evaluate the cost-effectiveness of preoperative short-course radiotherapy (SCRT, 5 × 5 Gy) plus FOLFOX4 versus long-course oxaliplatin and bolus of fluorouracil based preoperative long-course chemoradiotherapy (LCCRT, 50.4 Gy in 28 fractions) in the management of cT4 or advanced cT3 rectal cancer (RC), both of which have been reported to achieve similar clinical effect in the NCT00833131 trial.

MATERIALS AND METHODS

A Markov decision-analytic model compared SCRT plus chemotherapy and LCCRT, by simulating three health states (disease-free survival (DFS), progressive disease (PD) and death). The primary outcomes were quality-adjusted life months (QALMs), costs, and incremental cost-effectiveness ratios (ICERs). Transition probabilities were based on the NCT00833131 trial. The costs were calculated from a Chinese payers' perspective. Strategies were evaluated with a willingness-to-pay (WTP) threshold of $2370.47 (3 × GDP) per QALM gained. Sensitivity analysis was performed to model uncertainty in these parameters.

RESULTS

The overall costs for SCRT plus chemotherapy and LCCRT were $78,937 and $38,140 with effectiveness of 29.92 QALMs and 22.99 QALMs, respectively. SCRT plus chemotherapy increased costs and QALM by $40,797.34 and 6.93 compared to LCCRT, resulting in an ICER of $5884.56/QALM gained. In the DFS state, the whole cost for SCRT plus chemotherapy and LCCRT were $11,490.03 and $10,794.06 with an effectiveness of 21.70 QALMs and 19.65 QALMs, respectively. SCRT plus chemotherapy increased cost and QALM by $695.97 and 2.05 compared to LCCRT, resulting in a ICER of $339.50/QALM gained, which below the WTP. The utility associated with the DFS state was the most influential factor on the cost-effectiveness of SCRT plus chemotherapy. When the cost of PD state below $1920, the ICER of SCRT compared with LCCRT below the WTP.

CONCLUSION

Compared with LCCRT, SCRT plus chemotherapy is a more cost-effective strategy for locally advanced resectable RC in the DFS state as well as in the all states when the cost of PD state below $1920.

Local excision in mid-to-low rectal cancer patients who revealed clinically total or near-total regression after preoperative chemoradiotherapy; a proposed trial

Background

Preoperative chemoradiotherapy (pre-CRT) followed by total mesorectal excision (TME) is currently a standard therapy for locally advanced mid-to-low rectal cancer. Less aggressive, organ-preserving option such as local excision (LE) or watchful wait can alternatively be used for patients who respond well to pre-CRT. High-resolution rectal magnetic resonance imaging (MRI) is one of the most useful methods to assess pre-CRT response, and the MERCURY group has shown that the MR tumor regression grade (mrTRG) correlated with the pathologic TRG. The aim of this study is to compare postoperative complication and oncologic outcomes between LE and TME in mid-to-low rectal cancer patients whose tumors are mrTRG grade 1 (radiological complete remission) or 2 (predominant fibrosis; near-complete remission) after pre-CRT.

Methods

A prospective, double-arm, randomized, open-labeled, single center, clinical trial will be conducted in patients with mid-to-low rectal cancer whose tumors are mrTRG 1/2 after pre-CRT at the Asan Medical Center, Seoul, Korea, after approval from the Institution Review Board. Patient medical records will be de-identified using a serial number to protect personal information. Inclusion criteria will include rectal adenocarcinoma with an inferior border < 8 cm from the anal verge, mrTRG 1/2, age > 20, and provision of informed consent. Postoperative complications will be assessed by Clavien-Dindo Classification Grade. Oncologic and functional outcomes will be collected and risk factors related to these outcomes will be investigated.

Discussion

We believed that the rate of postoperative complication of LE will be comparable to that of TME in mid-to-low advanced rectal cancer patients with a favorable response after pre-CRT.

Trial registration

KCT0002579 (https://cris.nih.go.kr) Dec-2017.

Adjuvant radiation therapy for T4 non-rectal colon adenocarcinoma provides a cause-specific survival advantage: A SEER database analysis

PURPOSE

While there is no level 1 evidence supporting the use of adjuvant radiotherapy (RT) for non-rectal colon cancer in the modern chemotherapy era, there are studies that suggest a local control benefit. This treatment modality is not part of standard treatment recommendations, and we hypothesized that adjuvant RT provides a benefit in locally advanced disease. Due to the limited number who receive post-operative RT, a national database was searched to provide sufficient power.

MATERIALS AND METHODS

A retrospective analysis using the Surveillance, Epidemiology, and End Results (SEER) database was performed. Inclusion criteria were: non-rectal colon cancer, AJCC 6th or 7th edition T4 and M0, oncologic resection, and 1st cancer site. Patients were excluded for RT prior to or during surgery, or if the sequence of RT was unknown. Using a Cox proportional hazard model, the relative risk of cause-specific mortality for "RT after surgery" versus "No RT" was calculated.

RESULTS

21,789 patients were identified who met the inclusion criteria. Of these, only 1001 received adjuvant RT, and 64% were node-positive (53% RT vs. 65% no RT). When comparing RT vs. no RT, after adjusting for sex, age, N stage, and grade, we determined the relative risk of death from cancer was 0.8849 (95% CI: 0.8008-0.9779; p = 0.0165), suggesting that only 14 patients with T4 disease need receive adjuvant radiation to spare a cancer-related death.

CONCLUSIONS

Adjuvant RT is not routinely utilized for definitive treatment of T4 non-rectal colon cancer, but this analysis shows a significant cause-specific survival benefit.

Locally advanced rectal adenocarcinoma: Are preoperative short and long course radiotherapy truly equivalent?

In the neoadjuvant treatment of locally advanced rectal adenocarcinoma, long- and short-course radiotherapy are considered to be of equivalent efficacy based upon several randomized trials. The present study assessed the effect of radiotherapy dose on overall survival. Using the National Cancer Database (2006-2013) 458 individuals with clinical stage II/III rectal adenocarcinoma treated were identified, with either short- (25 Gy) or long- (45 or 50.4 Gy) course neoadjuvant radiotherapy followed by surgery, without neoadjuvant or adjuvant chemotherapy. Multivariate COX regression was employed to evaluate differences in overall survival according to radiotherapy regimen. An association with improved overall survival in individuals treated with long- compared with short-course radiotherapy was demonstrated (HR=0.50, 0.34-0.73). The 30- and 90-day post-surgery mortality rates were higher in the short-course group when compared with the long-course group (12.2 vs. 2.4%; and 18.5 vs. 5.4%, respectively). Following the exclusion of patients that succumbed within 90-days post-surgery, overall survival advantage in the long-course group compared with the short-course group was maintained [hazard ratio (HR)=0.62, 0.39-0.99], with a median overall survival of 25.3 months (IQR 16.9-41.6) for the short-course group compared with 43.5 months (IQR 25.6-67.9) for the long-course group. To the best of our knowledge, the present results suggest for the first time that long-course radiotherapy is associated with an improved overall survival compared with short-course radiotherapy in locally advanced rectal adenocarcinoma in the absence of chemotherapy usage. This possible advantage is clinically relevant mainly in patients who cannot tolerate systemic chemotherapy.

Phase I/II trial of nano-camptothecin CRLX101 with capecitabine and radiotherapy as neoadjuvant treatment for locally advanced rectal cancer

CRLX101 is a nanoparticle-drug conjugate with a camptothecin payload. We assessed the toxicity and pathologic complete response (pCR) rate of CRLX101 with standard neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer. A single-arm study was conducted with a 3 + 3 dose escalation phase Ib followed by phase II at the maximum tolerated dose (MTD). Thirty-two patients were enrolled with 29 (91%) patients having T3/4 and 26 (81%) N1/2 disease. In phase Ib, no patient experienced a dose limiting toxicity (DLT) with every other week dosing, while 1/9 patients experienced a DLT with weekly dosing. The weekly MTD was identified as 15 mg/m². The most common grade 3-4 toxicity was lymphopenia, with only 1 grade 4 event. pCR was achieved in 6/32 (19%) patients overall and 2/6 (33%) patients at the weekly MTD. CRLX101 at 15 mg/m² weekly with neoadjuvant CRT is a feasible combination strategy with an excellent toxicity profile. Clinicaltrials.gov registration NCT02010567.

Variation in the Height of Rectal Cancers According to the Diagnostic Modalities

Purpose

Although the height of a rectal tumor above the anal verge (tumor height) partly determines the treatment strategy, no practical standard exists for reporting this. We aimed to demonstrate the differences in tumor height according to the diagnostic modality used for its measurement.

Methods

We identified 100 patients with rectal cancers located within 15 cm of the anal verge who had recorded tumor heights measured by using magnetic resonance imaging (MRI), colonoscopy, and digital rectal examination (DRE). Tumor height measured by using MRI was compared with those measured by using DRE and colonoscopy to assess reporting inconsistencies. Factors associated with differences in tumor height among the modalities were also evaluated.

Results

The mean tumor heights were 77.8 ± 3.3, 52.9 ± 2.3, and 68.9 ± 3.1 mm when measured by using MRI, DRE, and colonoscopy, respectively (P < 0.001). Agreement among the 3 modalities in terms of tumor sublocation within the rectum was found in only 39% of the patients. In the univariate and the multivariate analyses, clinical stage showed a possible association with concordance among modalities, but age, sex, and luminal location of the tumor were not associated with differences among modalities.

Conclusion

The heights of rectal cancer differed according to the diagnostic modality. Tumor height has implications for rectal cancer’s surgical planning and for interpreting comparative studies. Hence, a consensus is needed for measuring and reporting tumor height.

Refining the Use of Adjuvant Oxaliplatin in Clinical Stage II or III Rectal Adenocarcinoma

BACKGROUND

Current guidelines include the use of adjuvant oxaliplatin in clinical stage II or III rectal adenocarcinoma. However, its efficacy is supported by a single phase II trial. We aimed to examine whether oxaliplatin confers survival benefit in this patient population.

METHODS

Using the National Cancer Database (2006-2013) we identified 6,868 individuals with clinical stage II or III rectal adenocarcinoma treated with neoadjuvant chemoradiotherapy, surgery, and adjuvant chemotherapy. We used multivariate Cox regression to evaluate survival differences according to treatment intensity and change from clinical to pathological stage.

RESULTS

We demonstrated an association with improved overall survival with the use of doublet adjuvant chemotherapy in pathological stage III rectal adenocarcinoma (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.67-0.92). This association was confirmed in patients with clinical stage III and subsequent pathological stage III disease (HR, 0.69; 95% CI, 0.57-0.83) and was not observed in patients who progressed from clinical stage II to pathological stage III disease. Doublet adjuvant chemotherapy was not associated with improved overall survival in patients with pathological stage 0 or I disease, regardless of their clinical stage.

CONCLUSION

Adjuvant oxaliplatin following neoadjuvant chemoradiotherapy in rectal adenocarcinoma was confirmed in patients with clinical stage III and subsequent pathological stage III disease. Omission of oxaliplatin can be considered in pathological complete response or pathological stage I disease.

IMPLICATIONS FOR PRACTICE

Current guidelines include the use of oxaliplatin as part of adjuvant chemotherapy (AC) in patients with clinical stage II or III rectal adenocarcinoma (RAC). However, its efficacy is supported only by a single phase II trial. This study found an association with improved overall survival with the use of doublet AC in patients diagnosed with clinical stage III and subsequent pathological stage III, and not in patients with pathological stage 0 or I, regardless of their clinical stage. Therefore, omission of oxaliplatin can be considered in patients with either pathological complete response or pathological stage I RAC, thereby avoiding oxaliplatin-induced neuropathy.

Recent advances of neoadjuvant chemoradiotherapy in rectal cancer: Future treatment perspectives

Neoadjuvant chemoradiotherapy (nCRT) has been widely used as a multidisciplinary approach for stage II/III rectal cancer. However, its safety and efficacy are controversial because previous studies have shown conflicting outcomes. The present review aimed to elucidate the benefits and limitations of nCRT for patients with rectal cancer. Future perspectives of nCRT are also described. No recent randomized trials have been able to show a survival benefit, although many studies have demonstrated good local control with the use of fluoropyrimidine (e.g. 5-fluorouracil [FU] or capecitabine)-based nCRT. Addition of oxaliplatin (OX) to FU-based nCRT might improve overall survival by preventing distant metastasis, as shown in recent meta-analyses. However, control of adverse effects is an important concern with this treatment. New treatment strategies such as nonoperative management (watch and wait policy) and total neoadjuvant therapy (TNT) are promising, but the establishment of reliable diagnostic methods of metastasis is essential. Development of new biomarkers is also necessary to select patients who are more likely to benefit from nCRT.

UGT1A1 polymorphisms in rectal cancer associated with the efficacy and toxicity of preoperative chemoradiotherapy using irinotecan

The purpose of the present study was to assess the efficacy and toxicity of preoperative chemoradiotherapy using irinotecan against locally advanced lower rectal cancer according to UDP-glucuronosyltransferase 1A1 (UGT1A1) polymorphisms. Between 2009 and 2016, 46 patients with resectable rectal cancer (T3-T4, N0-N2, M0) received preoperative chemoradiotherapy consisting of 80 mg/m2 per day tegafur/gimeracil/oteracil (S-1; days 1-5, 8-12, 22-26, and 29-33), 60 mg/m2 per day irinotecan (days 1, 8, 22, and 29), and 45 Gy radiation (1.8 Gy/day, 5 days per week for 5 weeks). Six to eight weeks after completing chemoradiotherapy, total mesorectal excision was carried out. Patients with UGT1A1 polymorphisms were divided into WT (n = 26), heterozygous (n = 15), and homozygous (n = 5) groups, the latter including double heterozygosities. We evaluated associations between clinical characteristics, including UGT1A1 polymorphisms, and chemoradiotherapy efficacy and toxicity. Incidence rates of grade 3+ neutropenia and diarrhea were 17.0% and 30.4%, respectively. Relative dose intensity was 89.3%. Pathological complete response rate (grade 3) was 26.1%, and the good response (grade 2/3) rate was 84.8%. UGT1A1 polymorphisms were significantly associated with neutropenia and pathological good responses, but not with diarrhea. UGT1A1 polymorphism was the only predictive factor for pathological good responses. Our results indicate that UGT1A1 polymorphism is a predictive factor to determine the clinical efficacy of preoperative chemoradiotherapy and hematological toxicity induced by chemoradiotherapy using irinotecan in locally advanced rectal cancer patients.

Comparative survival analysis of preoperative and postoperative radiotherapy in stage II-III rectal cancer on the basis of long-term population data

This study compared long-term population-based survival outcomes of preoperative and postoperative radiotherapy (RT) approaches in rectal cancer. Patients with stage II-III rectal cancer between 1998 and 2013 were identified using the Surveillance, Epidemiology, and End Results database. Overall survival (OS) and disease-specific survival (DSS) rates were estimated in propensity-matched study population according to the use of RT. Among the 28,320 eligible patients, a total of 18,400 patients were identified from propensity score matching process balancing the distribution of prognostic covariates. The 10-year OS and DSS rates were higher in patients with preoperative RT than the postoperative group (51.6% vs. 49.8% with P < 0.001, and 65.4% vs. 64.8% with P = 0.037, respectively). However, in multivariate analysis, selection of combined RT sequence did not affect the survival (hazard ratio [HR] 1.04 and 95% confidence interval [CI] 0.98−1.10 for OS; HR 0.97 and 95% CI 0.90−1.05 for DSS). Regarding hazard rate functions of cancer-specific mortality, the overall time-course risks after preoperative and postoperative RT were comparable. This study provides additional insight into the long-term prognostic implications of the two RT strategies, suggesting that the sequence of RT does not lead to differential survival in stage II-III rectal cancer.

Sarcopenia is poor prognostic factor in older patients with locally advanced rectal cancer who received preoperative or postoperative chemoradiotherapy

Sarcopenia is associated with low muscle mass and low physical performance. Here, we performed to evaluate the sarcopenia as prognostic factor and treatment outcomes in older patients with locally advanced rectal cancer (LARC) who received preoperative or postoperative chemoradiotherapy (CRT).LARC patients aged ≥65 years who received either preoperative or postoperative CRT were analyzed retrospectively. Preoperative or postoperative CRT consisted of 50.4 Gy and fluoropyrimidine. Surgery was performed at 6 weeks after CRT completion. Postoperative CRT was performed at 4 weeks after surgery. One month after surgery or CRT, adjuvant chemotherapy was given. Overall survival (OS) and disease free survival (DFS), local recurrence (LR), and prognostic factor were evaluated.Thirty patients received preoperative CRT and 35 patients received postoperative CRT. Five-year OS rate, 5-year DFS rate, or 5-year LR rate was not significantly different between preoperative and postoperative CRT groups (69.0%, 58.5%, and 3.4% vs 73.6%, 67.9%, and 6.9%, P = .56, P = .37, and P = .77, respectively). Age, sex, stage, CEA level, or timing of CRT did not affect OS. However, 5-year OS rate of patients with sarcopenia was significantly lower than those without sarcopenia (38.0% vs 92.5%, P < .001). Multivariate analysis showed that sarcopenia was the only independent prognostic factor for overall survival (OS) (hazard ratio [HR]: 6.08, P = .001).There was no difference in survival between preoperative CRT and postoperative CRT in older patients with LARC. Sarcopenia is a poor prognostic factor in older patients with LARC who received preoperative or postoperative CRT.

Patterns of failure in rectal cancer with positive circumferential resection margin after surgery following preoperative chemoradiation: a propensity score matching analysis

OBJECTIVE:

To compare the patterns of failure between rectal cancer patients with negative and positive circumferential resection margin (CRM) after surgery following preoperative chemoradiation.

METHODS:

Of 944 stage II-III rectal cancer patients treated with radical surgery following preoperative chemoradiation, 74 patients (7.8%) showed positive CRM. Each 72 patients from negative and positive CRM groups were identified by propensity score matching and compared in terms of survival outcomes and patterns of failure. Local failure was defined as recurrence at the anastomosis site or adjacent to the mesorectal fascia.

RESULTS:

The median follow-up was 46 months (range, 4-155). No difference was observed in 5-year local recurrence-free survival (93.4% vs 89.6%, p = 0.442) in the negative and positive CRM groups. There was statistically significant difference in relapse-free survival (57.1% vs 39.1%, p = 0.042). Negative CRM group showed favorable outcomes than positive CRM in distant metastasis-free survival (59.4% vs 43.3%, p = 0.069) and overall survival (67.5% vs 55.8%, p = 0.186), but the difference was not statistically significant. As the initial failure pattern, there were 30 and 43 recurrences in the negative and positive CRM groups (local 6.6 and 7.3%, regional 12.8 and 14.4%, and distant 38.5 and 54.9%). Isolated local recurrence was identified in two with negative CRM and in none with positive CRM (p = 0.497).

CONCLUSION:

Distant metastasis was the major pattern of failure regardless of CRM involvement in rectal cancer patients treated with surgery following preoperative chemoradiation. It would be taken account of our finding on adjuvant treatment for the patient with positive CRM.

ADVANCES IN KNOWLEDGE:

Investigation of the patterns of failure in patients with CRM involvement after preoperative chemoradiation followed by surgery can be conducive to selecting the appropriate approach to additional treatment for them.

Outcomes of patients in the national cancer database treated non-surgically for localized rectal cancer

Background

Some patients undergo a non-operative approach to localized rectal adenocarcinoma either because they decline surgery or because their medical comorbidities preclude surgical intervention. Published studies reporting excellent outcomes with a "wait-and-see" approach have been small and highly-selected. We aimed to analyze survival outcomes and prognostic factors for patients with localized rectal adenocarcinoma in the National Cancer Database (NCDB) undergoing definitive radiation without surgical intervention.

Methods

The NCDB was queried for patients with non-metastatic rectal adenocarcinoma treated with definitive radiotherapy who did not undergo a surgical resection either because the patient refused surgery, surgery was medically contraindicated, or surgery was otherwise unplanned. Patient, tumor and treatment-related characteristics were compared between those treated with 45-50.3 Gray (Gy), 50.4-54 Gy and >54 Gy. Survivals were compared using the Log-Rank test. Univariate and multivariate Cox regression analyses were performed. Survivals were then compared utilizing a robust inverse-probability-weighted regression adjustment method with nearest-neighbor matching.

Results

Eight thousand four hundred and eight patients were included for analysis. After case-matching and adjusting for significant prognostic factors, patients receiving 50.4-54 Gy had a significantly longer median, 1- and 5-year overall survival (OS) (49.4 months, 85.8%, 44.7%) compared with patients receiving 45-50.3 or >54 Gy (37.2 months, 79.2%, 38.4% and 34.2 months, 84.5%, 35.3%, respectively; Log rank P value <0.0001).

Conclusions

In an unselected group of patients treated at NCDB-participating institutions, survival rates with a non-surgical approach to non-metastatic rectal adenocarcinoma are much lower than those reported in well-selected single-institutional studies. Moderate dose escalation from 50.4-54 Gy was associated with better OS compared with doses <50.4 Gy or >54 Gy after adjusting for significant covariant.

The first thermic treatment predicts following chemoradiation response with concurrent thermal therapy for the treatment of rectal cancer

The present study aimed to evaluate whether the neoadjuvant chemoradiation response with concurrent thermal therapy for the treatment of rectal cancer can be predicted following the first thermic treatment. Eighty patients with primary rectal adenocarcinoma (≤12 cm from the anal verge) were included in this study. Fifty-four received surgery and pathological response was evaluated. Intensity-modulated radiotherapy was administered conventionally once daily 5 times/week. Neoadjuvant radiotherapy consisted of 50 Gy delivered to the planning target volume in 25 fractions. Concurrent neoadjuvant chemotherapy was delivered in 5-day courses. Capecitabine was administered orally at 1,700 mg/m²/day for 5 days/week. Thermic treatment was performed using the Thermotron-RF 8 and administered once/week for 5 weeks with 50 min irradiation. Patients with a gross tumor volume (GTV) ≤32 cm³ and a radiofrequency (RF) output difference (RO difference) ≥77 Watt/min exhibited pathological complete response (pCR) and CR rates of 50 and 75%, respectively. Those with a GTV ≥80 cm³ and a RO difference ≥77 Watt/min exhibited pCR and CR rates of 42.9 and 42.9%, respectively. The changes in the skin temperature during RF treatment in patients with pCR with a RO difference ≥77 Watt/min increased significantly compared with those of other outcomes, and progressive disease. These data suggest a strategy for predicting which patients will respond best following the first thermic treatment. The results identified that the group of patients with a GTV ≤32 cm³ and a RO difference ≥77 Watt/min (outputable/heatable patients) may respond best.