Five fractions of radiation therapy followed by 4 cycles of FOLFOX chemotherapy as preoperative treatment for rectal cancer

Recent advances in rectal cancer treatment - are we on the right track?

Background

Staging and treatment of rectal cancer have evolved over several decades with considerably fewer locoregional recurrences but no marked improved survival since systemic recurrence risks remain virtually unchanged. This development will briefly be summarised followed by a thorough discussion of two recent developments.

Methods

A systematic approach towards the literature is aimed at focusing on organ preservation and the delivery of all non-surgical treatments prior to surgery or total neoadjuvant treatment (TNT).

Results

Organ preservation, that is to defer surgery if the tumour happens to disappear completely after any pre-treatment given to locally advanced tumours to decrease recurrence risks has increased in popularity and is, if not universally, widely accepted. To give neo-adjuvant treatment to intentionally obtain a clinically complete remission to avoid surgery is practised in some environments but is mostly still experimental. TNT, that is to provide both radiotherapy and chemotherapy aimed at killing microscopic disease in the pelvis or elsewhere has been subject to several trials. Collectively, they show that the chance of achieving a complete response, pathologically or clinically, has approximately doubled, increasing the chance for organ preservation, and the risk of distant metastasis has decreased at least in some trials. The best schedule remains to be established.

Conclusions

To obtain substantial progress and also improve survival, the systemic treatments need to be improved even if preoperative delivery is more effective and better tolerated than postoperative. The locoregional treatment may be further optimised through better risk prediction.

Short-course radiation with consolidation chemotherapy does not increase operative morbidity compared to long-course chemoradiation: A retrospective study of the US rectal cancer consortium

BACKGROUND AND OBJECTIVES

Neoadjuvant short-course radiation and consolidation chemotherapy (SC TNT) remains less widely used for rectal cancer in the United States than long-course chemoradiation (LCRT). SC TNT may improve compliance and downstaging; however, a longer radiation-to-surgery interval may worsen pelvic fibrosis and morbidity with total mesorectal excision (TME). A single, US-center retrospective analysis has shown comparable risk of morbidity after neoadjuvant short-course radiation with consolidation chemotherapy (SC TNT) and long-course chemoradiation (LCRT). Validation by a multi-institutional study is needed.

METHODS

The US Rectal Cancer Consortium database (2010-2018) was retrospectively reviewed for patients with nonmetastatic, rectal adenocarcinoma treated with neoadjuvant LCRT or SC TNT before TME. The primary endpoint was severe postoperative morbidity. Cohorts were compared by univariate analysis. Multivariable logistic regression modeled the odds of severe complication.

RESULTS

Of 788 included patients, 151 (19%) received SC TNT and 637 (81%) LCRT. The SC TNT group had fewer distal tumors (33.8% vs. 50.2%, p < 0.0001) and more clinical node-positive disease (74.2% vs. 47.6%, p < 0.0001). The intraoperative complication rate was similar (SC TNT 5.3% vs. 4.4%, p = 0.65). There was no difference in overall postoperative morbidity (38.4% vs. 46.3%, p = 0.08). Severe morbidity was similar with low anterior resection (9.1% vs. 15.3%, p = 0.10) and abdominoperineal resection (24.4% vs. 29.7%, p = 0.49). SC TNT did not increase the odds of severe morbidity relative to LCRT on multivariable analysis (OR 0.64, 95% CI 0.37-1.10).

CONCLUSIONS

SC TNT does not increase morbidity after TME for rectal cancer relative to LCRT. Concern for surgical complications should not discourage the use of SC TNT when aiming to increase the likelihood of complete clinical response.

Neoadjuvant short-course radiotherapy or chemoradiation plus consolidative chemotherapy followed by radical operation for locally advanced rectal cancer

Introduction

Limited evidence compares short-course radiotherapy (SCRT) and long-course chemoradiotherapy (LCCRT), both of which are followed by consolidative chemotherapy before radical rectal surgery. We conducted a retrospective cohort study to assess treatment response, survival outcomes, and toxicity in patients with locally advanced rectal cancer.

Materials and methods

Patients (cT3-4 and/or N+) treated with SCRT or LCCRT, consolidative chemotherapy, or total mesorectal excision between 2013 and 2021 were identified. the cause-specific cumulative incidence of disease-related treatment failure, locoregional recurrence, distant metastases, and overall survival were evaluated using flexible parametric competing risk analysis and Kaplan-Meier methods, adjusted for treatment regimens and clinicopathological factors. A pathological complete response (pCR), tumor downstaging, and toxicity have been reported.

Results

Among the 144 patients, 115 (80%) underwent curative rectal surgery. The LCCRT and SCRT groups achieved pCR in 10 (18%) and seven (12%) patients, respectively (odds ratio, 1.68; 95% confidence interval [CI], 0.59-4.78). The adjusted cause-specific hazard ratio for disease-related treatment failure with LCCRT versus SCRT was 0.26 (95% CI, 0.08-0.87). Three-year cumulative probability of disease-related treatment failure was 10.0% and 25.6% for LCCRT and SCRT, respectively. No significant differences in T-downstaging, N-downstaging, significant pathologic downstaging (ypT0-2N0), locoregional failure, distant metastasis, or overall survival were found. Late rectal toxicity occurred in 10 (15%) LCCRT and two (3%) SCRT patients, respectively.

Conclusion

LCCRT with consolidative chemotherapy demonstrated improved disease-related treatment failure compared with SCRT, despite higher late rectal toxicity. Further research is needed to assess the long-term oncologic outcomes and toxicity.

Disparities in Clinical Trial Enrollment and Reporting in Rectal Cancer: A Systematic Review and Demographic Comparison to the National Cancer Database

BACKGROUND

Cancer care guidelines based on clinical trial data in homogenous populations may not be applicable to all rectal cancer patients. The aim of this study was to evaluate whether patients enrolled in rectal cancer clinical trials (CTs) are representative of United States (U.S.) rectal cancer patients.

METHODS

Prospective rectal cancer CTs from 2010 to 2019 in the United States were systematically reviewed. In trials with multiple arms reporting separate demographic variables, each arm was considered a separate CT group in the analysis. Demographic variables considered in the analysis were age, sex, race/ethnicity, facility location throughout the United States, rural vs urban geography, and facility type. Participant demographics from trial and the National Cancer Database (NCDB) participants were compared using chi-squared goodness of fit and one-sample t-test where applicable.

RESULTS

Of 50 CT groups identified, 42 (82%) studies reported mean or median age. Trial participants were younger compared to NCDB patients (P < .001 all studies). All but three trials had fewer female patients than NCDB (48.2% female, P < .001). Less than half the CT groups reported on race or ethnicity. Eighteen out of 22 trials (82%) had a smaller percentage of Black patients and 4 out of 8 (50%) trials had fewer Hispanic or Spanish origin patients than the NCDB. No CTs reported comorbidities, socioeconomic factors, or education. CT primary sites were largely at academic centers and in urban areas.

CONCLUSION

The present study supports the need for improved demographic representation and transparency in rectal cancer clinical trials.

Radiotherapy in the preoperative neoadjuvant treatment of locally advanced rectal cancer

Radiotherapy and chemotherapy are effective treatments for patients with locally advanced rectal cancer (LARC) and can significantly improve the likelihood of R0 resection. Radiotherapy can be used as a local treatment to reduce the size of the tumor, improve the success rate of surgery and reduce the residual cancer cells after surgery. Early chemotherapy can also downgrade the tumor and eliminate micrometastases throughout the body, reducing the risk of recurrence and metastasis. The advent of neoadjuvant concurrent radiotherapy (nCRT) and total neoadjuvant treatment (TNT) has brought substantial clinical benefits to patients with LARC. Even so, given increasing demand for organ preservation and quality of life and the disease becoming increasingly younger in its incidence profile, there is a need to further explore new neoadjuvant treatment options to further improve tumor remission rates and provide other opportunities for patients to choose watch-and-wait (W&W) strategies that avoid surgery. Targeted drugs and immunologic agents (ICIs) have shown good efficacy in patients with advanced rectal cancer but have not been commonly used in neoadjuvant therapy for patients with LARC. In this paper, we review several aspects of neoadjuvant therapy, including radiation therapy and chemotherapy drugs, immune drugs and targeted drugs used in combination with neoadjuvant therapy, with the aim of providing direction and thoughtful perspectives for LARC clinical treatment and research trials.

Combining chemotherapy and tislelizumab with preoperative split-course hypofraction radiotherapy for locally advanced rectal cancer: study protocol of a prospective, single-arm, phase II trial

INTRODUCTION

Short-course radiotherapy (SCRT) with systemic therapy has the potential to further improve the long-term efficacy in patients with locally advanced rectal cancer (LARC). To maximise the benefits of neoadjuvant therapy for improved prognosis, it is important to determine the optimal mix of chemotherapy, immunotherapy and SCRT.

METHODS AND ANALYSIS

Fifty treatment-naïve patients with operable LARC (T3-4 and/or N+) will be recruited. Patients will be synchronously treated with capecitabine plus oxaliplatin (CAPOX) chemotherapy, tislelizumab and preoperative split-course hypofraction radiotherapy (SCHR) (5×7 Gy) before surgery. Chemotherapy for CAPOX starts on day 1 of every 21-day cycle: on day 1, oxaliplatin 130 mg/m² will be injected intravenously. On days 1-14, capecitabine 1000 mg/m² was ingested two times a day. Simultaneously, tocilizumab 200 mg will be given intravenously on the first day of every 21-day cycle. A single 7 Gy SCHR treatment (day 7 of each 21-day cycle) will be delivered five times during the seventh day of treatment. The primary endpoint will be pathological complete response. The secondary outcomes will be the 3-year disease-free survival, local recurrence rate, overall survival, sphincter-sparing surgery rate, R0 resection rate, predictive biomarkers and quality of life.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of Xiehe Affiliated Hospital of Fujian Medical University (XAHFMU) (No. 2021YF025-01). Results from our study will be disseminated in international peer-reviewed journals. All study procedures were developed in order to assure data protection and confidentiality.

TRIAL REGISTRATION NUMBER

NCT05176964.

Consensus Quality Measures and Dose Constraints for Rectal Cancer From the Veterans Affairs Radiation Oncology Quality Surveillance Program and American Society for Radiation Oncology (ASTRO) Expert Panel

PURPOSE

Ensuring high quality, evidence-based radiation therapy for patients with cancer is of the upmost importance. To address this need, the Veterans Affairs (VA) Radiation Oncology Program partnered with the American Society for Radiation Oncology and established the VA Radiation Oncology Quality Surveillance program. As part of this ongoing effort to provide the highest quality of care for patients with rectal cancer, a blue-ribbon panel comprised of rectal cancer experts was formed to develop clinical quality measures.

METHODS AND MATERIALS

The Rectal Cancer Blue Ribbon panel developed quality, surveillance, and aspirational measures for (a) initial consultation and workup, (b) simulation, treatment planning, and treatment, and (c) follow-up. Twenty-two rectal cancer specific measures were developed (19 quality, 1 aspirational, and 2 surveillance). In addition, dose-volume histogram constraints for conventional and hypofractionated radiation therapy were created.

CONCLUSIONS

The quality measures and dose-volume histogram for rectal cancer serves as a guideline to assess the quality of care for patients with rectal cancer receiving radiation therapy. These quality measures will be used for quality surveillance for veterans receiving care both inside and outside the VA system to improve the quality of care for these patients.

Multicenter, Randomized, Phase III Trial of Short-Term Radiotherapy Plus Chemotherapy Versus Long-Term Chemoradiotherapy in Locally Advanced Rectal Cancer (STELLAR)

PURPOSE

To ascertain if preoperative short-term radiotherapy followed by chemotherapy is not inferior to a standard schedule of long-term chemoradiotherapy in patients with locally advanced rectal cancer.

MATERIALS AND METHODS

Patients with distal or middle-third, clinical primary tumor stage 3-4 and/or regional lymph node-positive rectal cancer were randomly assigned (1:1) to short-term radiotherapy (25 Gy in five fractions over 1 week) followed by four cycles of chemotherapy (total neoadjuvant therapy [TNT]) or chemoradiotherapy (50 Gy in 25 fractions over 5 weeks, concurrently with capecitabine [chemoradiotherapy; CRT]). Total mesorectal excision was undertaken 6-8 weeks after preoperative treatment, with two additional cycles of CAPOX (intravenous oxaliplatin [130 mg/m², once a day] on day 1 and capecitabine [1,000 mg/m², twice a day] from days 1 to 14) in the TNT group and six cycles of CAPOX in the CRT group. The primary end point was 3-year disease-free survival (DFS).

RESULTS

Between August 2015 and August 2018, a total of 599 patients were randomly assigned to receive TNT (n = 302) or CRT (n = 297). At a median follow-up of 35.0 months, 3-year DFS was 64.5% and 62.3% in TNT and CRT groups, respectively (hazard ratio, 0.883; one-sided 95% CI, not applicable to 1.11; P < .001 for noninferiority). There was no significant difference in metastasis-free survival or locoregional recurrence, but the TNT group had better 3-year overall survival than the CRT group (86.5% v 75.1%; P = .033). Treatment effects on DFS and overall survival were similar regardless of prognostic factors. The prevalence of acute grade III-V toxicities during preoperative treatment was 26.5% in the TNT group versus 12.6% in the CRT group (P < .001).

CONCLUSION

Short-term radiotherapy with preoperative chemotherapy followed by surgery was efficacious with acceptable toxicity and could be used as an alternative to CRT for locally advanced rectal cancer.

Total Neoadjuvant Therapy With Short-Course Radiation: US Experience of a Neoadjuvant Rectal Cancer Therapy

BACKGROUND

Short-course radiation followed by chemotherapy as total neoadjuvant therapy has been investigated primarily in Europe and Australia with increasing global acceptance. There are limited data on this regimen's use in the United States, however, potentially delaying implementation.

OBJECTIVE

This study aimed to compare clinical performance and oncologic outcomes of 2 rectal cancer neoadjuvant treatment modalities: short-course total neoadjuvant therapy versus standard chemoradiation.

DESIGN

This is a retrospective cohort study.

SETTING

This study was performed at a National Cancer Institute-designated cancer center.

PATIENTS

A total of 413 patients had locally advanced rectal cancers diagnosed from June 2009 to May 2018 and received either short-course total neoadjuvant therapy or standard chemoradiation.

INTERVENTIONS

There were 187 patients treated with short-course total neoadjuvant therapy (5 × 5 Gy radiation followed by consolidation oxaliplatin-based chemotherapy) compared with 226 chemoradiation recipients (approximately 50.4 Gy radiation in 28 fractions with concurrent fluorouracil equivalent).

MAIN OUTCOME MEASURES

Primary end points were tumor downstaging, measured by complete response and "low" neoadjuvant rectal score rates, and progression-free survival. Secondary analyses included treatment characteristics and completion, sphincter preservation, and recurrence rates.

RESULTS

Short-course total neoadjuvant therapy was associated with higher rates of complete response (26.2% vs 17.3%; p = 0.03) and "low" neoadjuvant rectal scores (40.1% vs 25.7%; p < 0.01) despite a higher burden of node-positive disease (78.6% vs 68.9%; p = 0.03). Short-course recipients also completed trimodal treatment more frequently (88.4% vs 50.4%; p < 0.01) and had fewer months with temporary stomas (4.8 vs 7.0; p < 0.01). Both regimens achieved comparable local control (local recurrence: 2.7% short-course total neoadjuvant therapy vs 2.2% chemoradiation, p = 0.76) and 2-year progression-free survival (88.2% short-course total neoadjuvant therapy (95% CI, 82.9-93.5) vs 85.6% chemoradiation (95% CI, 80.5-90.7)).

LIMITATIONS

Retrospective design, unbalanced disease severity, and variable dosing of neoadjuvant consolidation chemotherapy were limitations of this study.

CONCLUSIONS

Short-course total neoadjuvant therapy was associated with improved downstaging and similar progression-free survival compared with chemoradiation. These results were achieved with shortened radiation courses, improved treatment completion, and less time with diverting ostomies. Short-course total neoadjuvant therapy is an optimal regimen for locally advanced rectal cancer. See Video Abstract at http://links.lww.com/DCR/B724.TERAPIA NEOADYUVANTE TOTAL CON RADIACIÓN DE CORTA DURACIÓN: EXPERIENCIA ESTADOUNIDENSE DE UNA TERAPIA NEOADYUVANTE CONTRA EL CÁNCER DE RECTO.

ANTECEDENTES

La radiación de corta duración seguida de quimioterapia como terapia neoadyuvante total se ha investigado principalmente en Europa y Australia con una aceptación mundial cada vez mayor. Sin embargo, datos limitados sobre el uso de este régimen en los Estados Unidos, han potencialmente retrasando su implementación.

OBJETIVO

Comparar el desempeño clínico y los resultados oncológicos de dos modalidades de tratamiento neoadyuvante del cáncer de recto: terapia neoadyuvante total de corta duración versus quimioradiación. estándar.

DISEO

Cohorte retrospectivo.

AJUSTE

Centro oncológico designado por el NCI.

PACIENTES

Un total de 413 cánceres rectales localmente avanzados diagnosticados entre junio de 2009 y mayo de 2018 que recibieron cualquiera de los regímenes neoadyuvantes.

INTERVENCIONES

Hubo 187 pacientes tratados con terapia neoadyuvante total de ciclo corto (radiación 5 × 5 Gy seguida de quimioterapia de consolidación basada en oxaliplatino) en comparación con 226 pacientes de quimiorradiación (aproximadamente 50,4 Gy de radiación en 28 fracciones con equivalente de fluorouracilo concurrente).

PRINCIPALES MEDIDAS DE RESULTADO

Los criterios primarios de valoración fueron la disminución del estadio del tumor, medido por la respuesta completa y las tasas de puntuación rectal neoadyuvante "baja", y la supervivencia libre de progresión. Los análisis secundarios incluyeron las características del tratamiento y las tasas de finalización, conservación del esfínter y recurrencia.

RESULTADOS

La terapia neoadyuvante total de corta duración, se asoció con tasas más altas de respuesta completa (26,2% versus 17,3%, p = 0,03) y puntuaciones rectales neoadyuvantes "bajas" (40,1% versus 25,7%, p < 0,01) a pesar de una mayor carga de enfermedad con ganglios positivos (78,6% versus 68,9%, p = 0,03). Los pacientes de ciclo corto también completaron el tratamiento trimodal con mayor frecuencia (88,4% versus 50,4%, p < 0,01) y tuvieron menos meses con estomas temporales (4,8 versus 7,0, p < 0,01). Ambos regímenes lograron un control local comparable (recidiva local: 2,7% de SC-TNT versus 2,2% de TRC, p = 0,76) y supervivencia libre de progresión a 2 años (88,2% de SC-TNT [IC: 82,9 - 93,5] versus 85,6% CRT [CI: 80,5 - 90,7]).

LIMITACIONES

Diseño retrospectivo, gravedad de la enfermedad desequilibrada y dosificación variable de quimioterapia neoadyuvante de consolidación.

CONCLUSIONES

La terapia neoadyuvante total de ciclo corto se asoció con una mejora en la reducción del estadio y una supervivencia libre de progresión similar en comparación con la quimioradiación. Estos resultados se lograron con ciclos de radiación más cortos, tratamientos mejor finalizados y menos tiempo en ostomías de derivación. La terapia neoadyuvante total de corta duración es un régimen óptimo para el cáncer de recto localmente avanzado. Consulte Video Resumen en http://links.lww.com/DCR/B724. (Traducción- Dr. Fidel Ruiz Healy).

Perioperative Complications After Proctectomy for Rectal Cancer: Does Neoadjuvant Regimen Matter?

OBJECTIVE

Investigate the association between neoadjuvant treatment strategy and perioperative complications in patients undergoing proctectomy for nonmetastatic rectal cancer.

SUMMARY OF BACKGROUND DATA

Neoadjuvant SC-TNT is an alternative to neoadjuvant CRT for rectal cancer. Some have argued that short-course radiation and extended radiation-to-surgery intervals increase operative difficulty and complication risk. However, the association between SC-TNT and surgical complications has not been previously investigated.

METHODS

This single-center retrospective cohort study included patients undergoing total mesorectal excision for nonmetastatic rectal cancer after SC-TNT or CRT between 2010 and 2018. Univariate analysis of severe POM and multiple secondary outcomes, including overall POM, intraoperative complications, and resection margins, was performed. Logistic regression of severe POM was also performed.

RESULTS

Of 415 included patients, 156 (38%) received SC-TNT and 259 (62%) received CRT. The cohorts were largely similar, though patients with higher tumors (69.9% vs 47.5%, P < 0.0001) or node-positive disease (76.9% vs 62.6%, P = 0.004) were more likely to receive SC-TNT. We found no difference in incidence of severe POM (9.6% SC-TNT vs 12.0% CRT, P = 0.46) or overall POM (39.7% SC-TNT vs 37.5% CRT, P = 0.64) between cohorts. Neoadjuvant regimen was also not associated with a difference in severe POM (odds ratio 0.42, 95% confidence interval 0.04-4.70, P = 0.48) in multivariate analysis. There was no significant association between neoadjuvant regimen and any secondary outcome.

CONCLUSION

In rectal cancer patients treated with SC-TNT and proctectomy, we found no significant association with POM compared to patients undergoing CRT. SC-TNT does not significantly increase the risk of POM compared to CRT.

Cost-effectiveness of Total Neoadjuvant Therapy With Short-Course Radiotherapy for Resectable Locally Advanced Rectal Cancer

IMPORTANCE

Short-course radiotherapy and total neoadjuvant therapy (SCRT-TNT) followed by total mesorectal excision (TME) has emerged as a new treatment paradigm for patients with locally advanced rectal adenocarcinoma. However, the economic implication of this treatment strategy has not been compared with that of conventional long-course chemoradiotherapy (LCCRT) followed by TME with adjuvant chemotherapy.

OBJECTIVE

To perform a cost-effectiveness analysis of SCRT-TNT vs LCCRT in conjunction with TME for patients with locally advanced rectal cancer.

DESIGN, SETTING, AND PARTICIPANTS

A decision analytical model with a 5-year time horizon was constructed for patients with biopsy-proven, newly diagnosed, primary locally advanced rectal adenocarcinoma treated with SCRT-TNT or LCCRT. Markov modeling was used to model disease progression and patient survival after treatment in 3-month cycles. Data on probabilities and utilities were extracted from the literature. Costs were evaluated from the Medicare payer's perspective in 2020 US dollars. Sensitivity analyses were performed for key variables. Data were collected from October 3, 2020, to January 20, 2021, and analyzed from November 15, 2020, to April 25, 2021.

EXPOSURES

Two treatment strategies, SCRT-TNT vs LCCRT with adjuvant chemotherapy, were compared.

MAIN OUTCOMES AND MEASURES

Cost-effectiveness was evaluated using the incremental cost-effectiveness ratio and net monetary benefits. Effectiveness was defined as quality-adjusted life-years (QALYs). Both costs and QALYs were discounted at 3% annually. Willingness-to-pay threshold was set at $50 000/QALY.

RESULTS

During the 5-year horizon, the total cost was $41 355 and QALYs were 2.21 for SCRT-TNT; for LCCRT, the total cost was $54 827 and QALYs were 2.12, resulting in a negative incremental cost-effectiveness ratio (-$141 256.77). The net monetary benefit was $69 300 for SCRT-TNT and $51 060 for LCCRT. Sensitivity analyses using willingness to pay at $100 000/QALY and $150 000/QALY demonstrated the same conclusion.

CONCLUSIONS AND RELEVANCE

These findings suggest that SCRT-TNT followed by TME incurs lower cost and improved QALYs compared with conventional LCCRT followed by TME and adjuvant chemotherapy. These data offer further rationale to support SCRT-TNT as a novel cost-saving treatment paradigm in the management of locally advanced rectal cancer.

Adding Consolidation Capecitabine to Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: A Propensity-Matched Comparative Study

Aim

To determine whether adding consolidation capecitabine chemotherapy without lengthening the waiting period influences pathological complete response (pCR) and short-term outcome of locally advanced rectal cancer (LARC) receiving neoadjuvant chemoradiotherapy (NCRT).

Method

Totally, 545 LARC who received NCRT and radical resection between 2010 and 2018 were enrolled. Short-term outcome and pCR rate were compared between patients with and without additional consolidation capecitabine. Logistic analysis was performed to identify predictors of pCR.

Results

After propensity score matching, 229 patients were matched in both NCRT and NCRT-Cape groups. Postoperative morbidity was comparable between groups except for operation time, which is lower in the NCRT group (213.2 ± 67.4 vs. 227.9 ± 70.5, p = 0.025). Two groups achieved similar pCR rates (21.8 vs. 22.7%, p = 1.000). Tumor size (OR = 0.439, p < 0.001), time interval between NCRT and surgery (OR = 1.241, p = 0.003), and post-NCRT carcinoembryonic antigen (OR = 0.880, p = 0.008) were significantly correlated with pCR in patients with LARC. A predictive nomogram was constructed with a C-index of 0.787 and 0.741 on internal and external validation.

Conclusion

Adding consolidation capecitabine chemotherapy without lengthening CRT-to-surgery interval in LARC patients after NCRT does not seem to impact pCR or short-term outcome. A predictive nomogram for pCR was successful, and it could support treatment decision-making.

Current status of total neoadjuvant therapy for locally advanced rectal cancer

Neoadjuvant chemoradiotherapy (nCRT) plus total mesorectal excision (TME) has been the standard regimen for treatment of patients with locally advanced rectal cancer (LARC), because it significantly reduces the rate of local recurrence and enables sphincter preservation. However, distant metastasis remains the major reason for treatment failure, and the value of postoperative chemotherapy is still controversial. Recent studies have examined the use of total neoadjuvant therapy (TNT), defined as induction and/or consolidation chemotherapy (CONCT) with radiotherapy (RT) or nCRT prior to surgery. The results indicated that TNT may increase the rates of chemotherapy compliance and pathological complete response (pCR), and probably improve the success rate of sphincter preservation surgery. TNT may also improve disease-free survival and overall survival, and even reduce the rate of relapse. Here, we critically appraise the existing literature on three different TNT schemes used for LARC patients.

Clinical Complete Response in Patients With Rectal Adenocarcinoma Treated With Short-Course Radiation Therapy and Nonoperative Management

PURPOSE

This study aimed to determine the clinical efficacy and safety of nonoperative management (NOM) for patients with rectal cancer with a clinical complete response (cCR) after short-course radiation therapy and consolidation chemotherapy.

METHODS AND MATERIALS

Patients with stage I-III rectal adenocarcinoma underwent short-course radiation therapy followed by consolidation chemotherapy between January 2018 and May 2019 (n = 90). Clinical response was assessed by digital rectal examination, pelvic magnetic resonance imaging, and endoscopy. Of the patients with an evaluable initial response, those with a cCR (n = 43) underwent NOM, and those with a non-cCR (n = 43) underwent surgery. The clinical endpoints included local regrowth-free survival, regional control, distant metastasis-free survival, disease-free survival, and overall survival.

RESULTS

Compared with patients with an initial cCR, patients with initial non-cCR had more advanced T and N stage (P = .05), larger primary tumors (P = .002), and more circumferential resection margin involvement on diagnostic magnetic resonance imaging (P < .001). With a median follow-up of 30.1 months, the persistent cCR rate was 79% (30 of 38 patients) in the NOM cohort. The 2-year local regrowth-free survival was 81% (95% confidence interval [CI], 70%-94%) in the initial cCR group, and all patients with local regrowth were successfully salvaged. Compared with those with a non-cCR, patients with a cCR had improved 2-year regional control (98% [95% CI, 93%-100%] vs 85% [95% CI, 74%-97%], P = .02), distant metastasis-free survival (100% [95% CI, 100%-100%] vs 80% [95% CI, 69%-94%], P < .01), disease-free survival (98% [95% CI, 93%-100%] vs 71% [95% CI, 59%-87%], P < .01), and overall survival (100% [95% CI, 100%-100%] vs 88% [95% CI, 79%-98%], P = .02). No late grade 3+ gastrointestinal or genitourinary toxicities were observed in the patients who underwent continued NOM.

CONCLUSIONS

Short-course radiation therapy followed by consolidation chemotherapy may be a feasible organ preservation strategy in rectal cancer. Additional prospective studies are necessary to evaluate the safety and efficacy of this approach.

Neoadjuvant short-course radiotherapy with consolidation chemotherapy for locally advanced rectal cancer: a systematic review and meta-analysis

BACKGROUND

Short-course radiotherapy with consolidation chemotherapy (SCRT-CCT) has emerged as a promising alternative to the long course chemoradiotherapy (LCRT) regimen in locally advanced rectal cancer management. The systematic review and meta-analysis is aimed at summarizing current evidence on SCRT-CCT and comparing it to LCRT.

MATERIAL AND METHODS

Electronic databases of MEDLINE, Web of Science, and Cochrane library were searched using a predefined search strategy returning 3314 articles. This review included 11 studies (6 randomized trials and 5 non-randomized studies) on SCRT-CCT regimen based on seven different cohorts. Weighted arithmetic means and forest plots were generated to determine summary estimates.

RESULTS

The probability of achieving pathological complete response (pCR) was higher with SCRT-CCT compared to LCRT (risk ratio [RR] = 1.75, 95% confidence interval [CI]: 1.41-2.19). No statistically significant difference in 3-year overall survival (OS) was observed between the two groups (RR= 1.06, 95% CI: 0.98-1.14). The weighted arithmetic mean of 3-year OS and pCR was 83.6% versus 80.9%, and 24.5% versus 13.6% for SCRT-CCT and LCRT, respectively. R0 resection and T-downstaging rates ranged from 69.2-100% to 47-75% for SCRT-CCT, and 71-92.3% and 41-75% for LCRT, respectively. The regimens had similar compliance, postoperative, and late toxicity, however, acute toxicity rates varied primarily due to differences in treatment protocols.

CONCLUSIONS

This review highlights the ability of SCRT-CCT to produce improved tumor response with comparable OS, R0 resection, and T-downstaging at the cost of increased acute toxicity. However, heterogeneity in treatment protocols across studies makes it difficult to provide definitive conclusions regarding the regimen. Several ongoing trials are expected to provide further evidence confirming the findings of RAPIDO trial and detail appropriate SCRT-CCT protocols to improve oncological outcomes, minimize toxicity, and determine its effectiveness as the standard-of-care for locally advanced rectal cancer patients.

Neoadjuvant Capecitabine and Oxaliplatin Before Concurrent Capecitabine and Radiation in Locally Advanced Rectal Cancers: Experience of a Cancer Hospital in Pakistan

To report the toxicity and pathologic response rates after adding neoadjuvant capecitabine and oxaliplatin (CAPOX) followed by concurrent radiation and capecitabine (CAPRT) and surgery in patients with locally advanced rectal cancer.

Immunity, immunotherapy, and rectal cancer: A clinical and translational science review

Rectal cancer remains a challenging disease to treat. Therapy for locally advanced rectal cancer (LARC), the most frequent presentation, has evolved to include a multimodal approach of radiation, chemotherapy, and surgery. While this approach improves local disease control, the distant recurrence rate is nearly 30% and treatment-related morbidity is substantial, thus underscoring the need for new therapeutic approaches with better efficacy and lower side effects. Immunotherapy could potentially fill this need, but its promise is not yet realized in rectal cancer. In this translational science review, we address what is known about how cytotoxic therapies shape rectal cancer immunity and potentially prime the tumor microenvironment for response to immune checkpoint inhibitors and other immunotherapies. We also address the role of current immunotherapies in colorectal cancer and highlight where novel immunotherapy approaches are currently being evaluated in LARC. Finally, we address important future directions in LARC immunotherapy including the need to define optimal therapeutic sequencing, predictive biomarkers, strategies to limit treatment-related side effects and the potential of gut microbiome manipulation to improve outcomes. In summary, this review provides a framework to guide future research and inform immunotherapy trial design so as to advance rectal cancer care.

Curative therapy for rectal cancer

Introduction: A comprehensive trimodality approach has become the standard of care for patients with locally advanced rectal cancer. However, the sequencing and duration of chemotherapy and chemoradiotherapy around surgery varies between clinical studies and geographical regions. Growing evidence is also mounting for strategies such as total neoadjuvant therapy and non-operative management for carefully selected patients.Areas covered: We provide a perspective review of the current evidence and controversies in the treatment of locally advanced rectal cancer including the recent updates from the 2020 ASCO annual conference.Expert opinion: With ongoing advances in the management of locally advanced rectal cancer, a multidisciplinary team approach is necessary as treatments could involve multiple approaches. Chemoradiotherapy whether short or long course followed by at least 3 months of systemic chemotherapy may be the preferred option to balance local and distant disease control. Albeit the choice of doublet or triplet chemotherapy is still controversial. As total neoadjuvant treatment becomes part of the standard of care in rectal cancer, modification of the surveillance schedule is needed to detect early recurrences which may be limited by resources and availability of services.

Watch and wait approach in rectal cancer: Current controversies and future directions

According to the main international clinical guidelines, the recommended treatment for locally-advanced rectal cancer is neoadjuvant chemoradiotherapy followed by surgery. However, doubts have been raised about the appropriate definition of clinical complete response (cCR) after neoadjuvant therapy and the role of surgery in patients who achieve a cCR. Surgical resection is associated with significant morbidity and decreased quality of life (QoL), which is especially relevant given the favourable prognosis in this patient subset. Accordingly, there has been a growing interest in alternative approaches with less morbidity, including the organ-preserving watch and wait strategy, in which surgery is omitted in patients who have achieved a cCR. These patients are managed with a specific follow-up protocol to ensure adequate cancer control, including the early identification of recurrent disease. However, there are several open questions about this strategy, including patient selection, the clinical and radiological criteria to accurately determine cCR, the duration of neoadjuvant treatment, the role of dose intensification (chemotherapy and/or radiotherapy), optimal follow-up protocols, and the future perspectives of this approach. In the present review, we summarize the available evidence on the watch and wait strategy in this clinical scenario, including ongoing clinical trials, QoL in these patients, and the controversies surrounding this treatment approach.

Short-course versus long-course neoadjuvant chemoradiotherapy in patients with rectal cancer: preliminary results of a randomized controlled trial

Purpose

Colorectal cancer is becoming an increasing concern in the middle-aged population of Iran. This study aimed to compare the preliminary results of short-course and long-course neoadjuvant chemoradiotherapy treatment for rectal cancer patients.

Materials and Methods

In this clinical trial we recruited patients with rectal adenocarcinoma located from 5 cm to 15 cm above the anal verge. Patients in group I (short-course) received three-dimensional conformational radiotherapy with a dose of 25 Gy/5 fractions in 1 week plus concurrent XELOX regimen (capecitabine 625 mg/m² from day 1–5 twice daily and oxaliplatin 50 mg/m² on day 1 once daily). Patients in group II (long-course) received a total dose of 50–50.4 Gy/25–28 fractions for 5 to 5.5 weeks plus capecitabine 825 mg/m² twice daily. Both groups underwent consolidation chemotherapy followed by delayed surgery at least 8 weeks after radiotherapy completion. The pathological response was assessed with tumor regression grade.

Results

In this preliminary report on complications and pathological response, 66 patients were randomized into two study groups. Mean duration of radiotherapy in groups I and II was 5 ± 1 days (range, 5 to 8 days) and 38 ± 6 days (range, 30 to 58 days). The median follow-up was 18 months. Pathological complete response was achieved in 32.3% and 23.1% of patients in the short-course and long-course groups, respectively (p = 0.558). Overall, acute grade 3 or higher treatment-related toxicities occurred in 24.2% and 22.2% of patients in group I and II, respectively (p = 0.551). No acute grade 4 or 5 adverse events were observed in either group except one grade 4 hematologic toxicity that was seen in group II. Within one month of surgery, no significant difference was seen regarding grade ≥3 postoperative complications (p = 0.333).

Conclusion

For patients with rectal cancer located at least 5 cm above the anal verge, short-course radiotherapy with concurrent and consolidation chemotherapy and delayed surgery is not different in terms of acute toxicity, postoperative morbidity, complete resection, and pathological response compared to long-course chemoradiotherapy.

Management of Locally Advanced Rectal Cancer During The COVID-19 Pandemic: A Necessary Paradigm Change at Memorial Sloan Kettering Cancer Center

The COVID-19 pandemic will consume significant health care resources. Given the concerns for rapidly increasing infection rates in the United States, impending staffing shortages, and the potential for resource reallocation, we rapidly reevaluated our rectal cancer practice policies during this public health emergency. Before the pandemic, we commonly used total neoadjuvant therapy with a strong preference for long-course chemoradiation. In the setting of the ongoing pandemic, we now mandate short-course radiation therapy (SCRT). Despite multiple randomized trials demonstrating no difference in locoregional recurrence, distant recurrence, or overall survival between SCRT and long-course chemoradiation, the adaptation of SCRT in the United States has been low given concerns for less tumor downstaging and increased toxicity. In the setting of the ongoing and likely prolonged COVID-19 pandemic, we feel that these concerns must be reevaluated, because SCRT presents a well-validated alternative that will allow us to meet the needs of a greater number of potentially curable patients at a time when resources are severely and acutely constrained.

The effect of neoadjuvant short-course radiotherapy and delayed surgery versus chemoradiation on postoperative outcomes in locally advanced rectal cancer patients - A propensity score matched nationwide audit-based study

OBJECTIVE

To investigate differences in postoperative outcomes between short-course radiotherapy and delayed surgery (SCRT-delay) and chemoradiation (CRT) in patients with locally advanced rectal cancer (LARC).

BACKGROUND

Previous trials suggest that SCRT-delay could serve as an adequate neoadjuvant treatment for LARC. Therefore, in frail LARC patients SCRT-delay is recommended as an alternative to CRT. However, data on postoperative outcomes after SCRT-delay in comparison to CRT is scarce.

METHODS

This was an observational study with data from the Dutch ColoRectal Audit (DCRA). LARC patients who underwent surgery (2014-2017) after an interval of ≥6 weeks were included. Missing values were replaced by multiple imputation. Propensity score matching (PSM), using age, Charlson Comorbidity Index, cT-stage and surgical procedure, was applied to create comparable groups. Differences in postoperative outcomes were analyzed using Chi-square test for categorical variables, independent sample t-test for continuous variables and Mann-Whitney U test for non-parametric data.

RESULTS

2926 patients were included. In total, 288 patients received SCRT-delay and 2638 patients underwent CRT. Patients in the SCRT-delay group were older and had more comorbidities. Also, ICU-admissions and permanent colostomies were more common, as well as pulmonic, cardiologic, infectious and neurologic complications. After PSM, both groups comprised 246 patients with equivalent age, comorbidities and tumor stage. There were no differences in postoperative complications.

CONCLUSION

Postoperative complications were not increased in LARC patients undergoing SCRT-delay as neoadjuvant treatment. Regarding treatment-related complications, SCRT-delay is a safe alternative neoadjuvant treatment option for frail LARC patients.

Dose-time fractionation schedules of preoperative radiotherapy and timing to surgery for rectal cancer

Chemoradiotherapy (CRT) is extensively used prior to surgery for rectal cancer to provide significantly better local control, but the radiotherapy (RT), as the other component of CRT, has been subject to less interest than the drug component in recent years. With considerable developments in RT, the use of advanced techniques, such as intensity-modulated radiotherapy (IMRT) in rectal cancer, is garnering more attention nowadays. The radiation dose can be better conformed to the target volumes with possibilities for synchronous integrated boost without increased complications in normal tissue. Hopefully, both local recurrence and toxicities can be further reduced. Although those seem to be of interest, many issues remain unresolved. There is no international consensus regarding the radiation schedule for preoperative RT for rectal cancer. Moreover, an enormous disparity exists regarding the RT delivery. With the advent of IMRT, variations will likely increase. Moreover, time to surgery is also quite variable, as it depends upon the indication for RT/CRT in the clinical practices. In this review, we discuss the options and problems related to both the dose-time fractionation schedule and time to surgery; furthermore, it addresses the research questions that need answering in the future.

Emerging trends in the treatment of rectal cancer

The conventional treatment for cT3-T4 or node-positive clinically resectable rectal cancer is long course preoperative chemoradiation followed by surgery and postoperative adjuvant chemotherapy. Disadvantages of this approach include possible overtreatment of patients, 6 weeks of daily radiation treatment, and undetected metastatic disease. There are a number of emerging trends which are changing this approach to treatment. Selected topics included in this manuscript include the selective use of pelvic radiation, the role of radiation for a positive radial margin, the interval between radiation and surgery, non-operative management, new chemoradiation regimens, short vs. long course radiation, and the role of postoperative adjuvant chemotherapy.

Robust dose planning objectives for mesorectal radiotherapy of early stage rectal cancer - A multicentre dose planning study

BACKGROUND AND PURPOSE

Organ preservation strategies are increasingly being explored for early rectal cancer. This requires revision of target volumes according to disease stage, as well as new guidelines for treatment planning. We conducted an international, multicentre dose planning study to develop robust planning objectives for modern radiotherapy of a novel mesorectal-only target volume, as implemented in the STAR-TReC trial (NCT02945566).

MATERIALS AND METHODS

The published literature was used to establish relevant dose levels for organ at risk (OAR) plan optimisation. Ten representative patients with early rectal cancer were identified. Treatment scans had mesorectal target volumes as well as bowel cavity, bladder and femoral heads outlined, and were circulated amongst the three participating institutions. Each institution produced plans for short course (SCRT, 5 × 5 Gy) and long course (LCRT, 25 × 2 Gy) treatment, using volumetric modulated arc therapy on different dose planning systems. Optimisation objectives for OARs were established by determining dose metric objectives achievable for ≥90% of plans.

RESULTS

Sixty plans, all fulfilling target coverage criteria, were produced. The planning results and literature review suggested optimisation objectives for SCRT: V 10Gy < 180 cm3, V 18Gy < 110 cm3, V 23Gy < 85 cm3 for bowel cavity; V 21Gy < 15% and V 25Gy < 5% for bladder; and V 12.5Gy < 11% for femoral heads. Corresponding objectives for LCRT: V 20Gy < 180 cm3, V 30Gy < 130 cm3, V 45Gy < 90 cm3 for bowel cavity; V 35Gy < 22% and V 50Gy < 7% for bladder; and V 25Gy < 15% for femoral heads. Constraints were validated across all three institutions.

CONCLUSION

We utilized a multicentre planning study approach to develop robust planning objectives for mesorectal radiotherapy for early rectal cancer.

Non-operative management of rectal cancer

Despite advances in technique, surgical resection of rectal cancer remains a morbid procedure that can lead a profound decrease in a patient's quality of life. A novel method of management, termed "Non-operative management" (NOM), mirrors the management of anal carcinoma. Patients undergo definitive treatment with only chemotherapy and radiation, with resection reserved only for salvage. Current data is encouraging- both in reduction in morbidity and similar, if not superior oncologic results. However, there are a number of barriers to the wide adoption of this practice. This manuscript seeks to describe the rationale and execution of NOM as well as present the current data and pitfalls of the approach.

Phase 1 Study of Neoadjuvant Short-Course Radiation Therapy Concurrent With Infusional 5-Fluorouracil for the Treatment of Locally Advanced Rectal Cancer

Purpose

To assess the safety and feasibility of neoadjuvant short-course radiation therapy (RT) concurrent with continuous infusion 5-fluorouracil (5-FU) for the treatment of locally advanced rectal cancer.

Methods and Materials

Patients with cT3-4 or N + rectal adenocarcinoma based on ultrasound or magnetic resonance imaging were prospectively enrolled in this study. Study treatment consisted of continuous infusion 5-FU combined with short-course RT (5 Gy x 5 fractions) followed by 4 cycles of mFOLFOX, total mesorectal excision (TME), and 6 cycles of adjuvant mFOLFOX. To mitigate the potential added toxicity from concurrent 5-FU, intensity modulated RT was used. Using the continual reassessment method, the dose of 5-FU was escalated from 100 to a maximum-tolerated dose of 200 mg/m²/d.

Results

Fourteen patients were accrued. All patients completed continuous infusion 5-FU and short-course RT and the 5-FU dose was safely escalated to 200 mg/m²/d with no dose-limiting toxicity. Thirteen patients received the neoadjuvant mFOLFOX, and only 1 patient went straight to surgery after chemoradiation. Clinical response was 21% complete, 63% partial, 14% stable disease, and no patients had progression. Three patients with cCR had negative biopsies and did not have TME. Pathologic response was 64% partial response and 14% stable disease. No patients had pathologic progression. The most common grade 3 and 4 toxicities were cytopenias. The most common grade 1 and 2 toxicities were cytopenia, fatigue, diarrhea, and nausea.

Conclusions

Our findings suggest that concurrent chemotherapy with neoadjuvant short-course RT is feasible and can be safely given with concurrent continuous infusion 5-FU. This works adds to the growing evidence that short-course RT is not only equivalent to long-course RT, but also may provide additional benefits, such as allowing for a transition to full dose systemic therapy in the neoadjuvant setting, selective organ preservation in complete responders, and providing a more convenient and cost-effective way of delivering pelvic RT.

Dose escalation of preoperative short-course radiotherapy followed by neoadjuvant chemotherapy in locally advanced rectal cancer: protocol for an open-label, single-centre, phase I clinical trial

INTRODUCTION

Preoperative radiotherapy followed by total mesorectal excision with adjuvant chemotherapy has been recommended as the preferred treatment method for locally advanced rectal cancer (LARC). Similar rates of local control, survival and toxicity were observed in preoperative long-course chemoradiotherapy (LCRT) (45-50.4 Gy in 25-28 fractions) and in short-course radiotherapy (SCRT) with 25 Gy over five fractions. Both regimens lower the local recurrence rates compared with that of surgery followed by postoperative radiotherapy. With the simplicity and lower cost of SCRT, a growing number of patients have been receiving SCRT as preoperative radiotherapy. However, the currently established SCRT (25 Gy over five fractions) followed immediately by surgery resulted in poor downstaging and sphincter preservation rate. The pathological complete response (pCR) rate is also markedly lower with SCRT than with LCRT (0.7%vs16%). Several studies recommended SCRT with delayed surgery for more than 4 weeks with expectation of improved pathological outcomes and fewer postoperative complications. While a number of clinical trials demonstrated a persistently better overall local control with SCRT than with LCRT, overall survival advantage has not been observed. Since survival is mainly depended on distant metastases, efforts should be made towards more effective pathological response and systemic treatment. Given the apparent advantages of SCRT, we aimed to establish a dose escalation of SCRT and sequential modified FOLFOX6 (mFOLFOX6) as preoperative therapy for LARC with objectives of achieving an optimal balance of safety, cost effectiveness and clinical outcome, and to support further investigation of this regimen in a phase II/III setting.

METHODS

In this phase I study, three dose levels (6Gy×5F, 7Gy×5F, 8Gy×5F to gross tumour volume, while keeping the rest of irradiated volume at 5Gy×5) of SCRT followed by four cycles of mFOLFOX6 chemotherapy as neoadjuvant therapy will be tested by using the traditional 3+3 design. The pCR rate, R0 resection rate, sphincter preservation rate and treatment related toxicity will be assessed.

ETHICS AND DISSEMINATION

The study protocol was approved by the Ethics Committee of Fujian Medical University Union Hospital (No. 2017YF020-02) and all participants provided written informed consent. Results from our study will be disseminated in international peer-reviewed journals. All study procedures were developed in order to assure data protection and confidentiality.

TRIAL REGISTRATION NUMBER

NCT03466424; Pre-results.

Consolidation mFOLFOX6 Chemotherapy After Chemoradiotherapy Improves Survival in Patients With Locally Advanced Rectal Cancer: Final Results of a Multicenter Phase II Trial

BACKGROUND

Adding modified FOLFOX6 (folinic acid, fluorouracil, and oxaliplatin) after chemoradiotherapy and lengthening the chemoradiotherapy-to-surgery interval is associated with an increase in the proportion of rectal cancer patients with a pathological complete response.

OBJECTIVE

The purpose of this study was to analyze disease-free and overall survival.

DESIGN

This was a nonrandomized phase II trial.

SETTINGS

The study was conducted at multiple institutions.

PATIENTS

Four sequential study groups with stage II or III rectal cancer were included.

INTERVENTION

All of the patients received 50 Gy of radiation with concurrent continuous infusion of fluorouracil for 5 weeks. Patients in each group received 0, 2, 4, or 6 cycles of modified FOLFOX6 after chemoradiation and before total mesorectal excision. Patients were recommended to receive adjuvant chemotherapy after surgery to complete a total of 8 cycles of modified FOLFOX6.

MAIN OUTCOME MEASURES

The trial was powered to detect differences in pathological complete response, which was reported previously. Disease-free and overall survival are the main outcomes for the current study.

RESULTS

Of 259 patients, 211 had a complete follow-up. Median follow-up was 59 months (range, 9-125 mo). The mean number of total chemotherapy cycles differed among the 4 groups (p = 0.002), because one third of patients in the group assigned to no preoperative FOLFOX did not receive any adjuvant chemotherapy. Disease-free survival was significantly associated with study group, ypTNM stage, and pathological complete response (p = 0.004, <0.001, and 0.001). A secondary analysis including only patients who received ≥1 cycle of FOLFOX still showed differences in survival between study groups (p = 0.03).

LIMITATIONS

The trial was not randomized and was not powered to show differences in survival. Survival data were not available for 19% of the patients.

CONCLUSIONS

Adding modified FOLFOX6 after chemoradiotherapy and before total mesorectal excision increases compliance with systemic chemotherapy and disease-free survival in patients with locally advanced rectal cancer. Neoadjuvant consolidation chemotherapy may have benefits beyond increasing pathological complete response rates. See Video Abstract at http://links.lww.com/DCR/A739.

Neoadjuvant therapy and subsequent treatment in rectal cancer: balance between oncological and functional outcomes

Current practice of neoadjuvant therapy and total mesorectal excision (TME) in rectal cancer bears the weakness in systemic disease control and long-term functional outcomes. With increasing concerns of the balance between cure and quality of life, new strategies are developed to better oncological outcomes at least cost of function damage. Attractive options to adjust neoadjuvant modality include escalation of radiotherapy, intensification of chemotherapy, and chemoradiotherapy with consolidation or full-course chemotherapy. Subsequently, organ-preserving strategies have gained the popularity. Surgical or nonsurgical approaches that spare the rectum are used as possible alternatives for radical surgery, though high-quality TME remains the last resort to offer reliable local disease control. This review discusses new strategies of neoadjuvant therapy and subsequent management, with a specific focus on the balance between oncological and functional outcomes.

A Randomized Phase 2 Trial of Consolidation Chemotherapy After Preoperative Chemoradiation Therapy Versus Chemoradiation Therapy Alone for Locally Advanced Rectal Cancer: KCSG CO 14-03

PURPOSE

Preoperative chemoradiation therapy (CRT) followed by total mesorectal excision (TME) in locally advanced rectal cancer is the standard of care. To date, the role of consolidation chemotherapy after CRT has rarely been addressed through randomized trials. This study aimed to evaluate the efficacy of CRT followed by consolidation chemotherapy compared with CRT alone.

METHODS AND MATERIALS

This study enrolled patients with adenocarcinoma of the rectum and cT3 or cT4 disease with any N category and no metastasis. In arm A (control arm), we planned CRT (50.4 Gy in 28 fractions) with capecitabine followed by TME. In arm B, 2 cycles of capecitabine and oxaliplatin were administered 1 week after the completion of CRT before TME (capecitabine, 1700 mg/m² per day from day 1 to 14, and oxaliplatin, 100 mg/m² on day 1, every 3 weeks). The downstaging rate (the proportion of ypT0 to ypT2 and ypN0M0) was the primary endpoint, which was to be tested with a 1-sided type I error of 15% and with 85% power.

RESULTS

From September 2014 to February 2016, 110 patients (56 in arm A and 54 in arm B) were randomized and 108 (55 in arm A and 53 in arm B) started CRT. TME was conducted per protocol in 96 patients (52 in arm A and 44 in arm B). In arms A and B, downstaging was achieved in 21.2% and 36.4% (P = .077), respectively, and the pathologic complete response rate was 5.8% and 13.6% (P = .167), respectively. Grade ≥3 adverse events occurred in 3.6% of patients in arm A and 9.4% of patients in arm B during the preoperative treatment phase and in 1.9% and 9.0%, respectively, during the postoperative recovery phase.

CONCLUSIONS

Consolidation chemotherapy with 2 cycles of capecitabine and oxaliplatin demonstrated a marginal improvement in the downstaging rate. However, a phase 3 trial of this strategy is discouraged because of the high dropout rate and safety issues.

Neoadjuvant Treatment Strategies: Advanced Radiation Alternatives

Long-course chemoradiation therapy (CRT) has been the standard approach for locally advanced rectal tumors. Neoadjuvant CRT is associated to improved local disease control, with less toxicity when compared with adjuvant CRT, as well as the chance for pathologic complete response. The CRT regimens have improved over the past years. This article will examine selected controversies, including novel chemoradiation regimens, duration of radiation (short vs. long course), and radiation techniques such as intensity-modulated radiation therapy (IMRT).

Current issues of preoperative radio(chemo)therapy and its future evolution in locally advanced rectal cancer

Neoadjuvant therapies are effective for local control and tumor downstaging. Up to date, preoperative long-course chemoradiotherapy and short-course radiotherapy are the two primary guideline-recommended neoadjuvant therapies for locally advanced rectal cancer patients. However, clinicians throughout the world are trying their best to further optimize the regimens and concepts of neoadjuvants. Hence, there is an urgent need to summarize evidence regarding indications of neaoadjuvant therapies and relative merits of current standard regimens. In addition, we also reviewed the optimized regimens mainly based on short-course radiotherapy with delayed surgery, consolidation chemotherapy, induction chemotherapy, chemotherapy alone without radiation and concepts in terms of organ preservation and personalized treatments to further explore the future evolution of neoadjuvant therapies in rectal cancer.

Improved Metastasis- and Disease-Free Survival With Preoperative Sequential Short-Course Radiation Therapy and FOLFOX Chemotherapy for Rectal Cancer Compared With Neoadjuvant Long-Course Chemoradiotherapy: Results of a Matched Pair Analysis

PURPOSE

To compare treatment and toxicity outcomes between a phase 2 institutional trial of near total neoadjuvant therapy (nTNT) for locally advanced rectal cancer and a similar historical control cohort treated at Washington University in St. Louis with the current US standard of care, defined as neoadjuvant chemoradiotherapy (NCRT), total mesorectal excision (TME), and adjuvant FOLFOX chemotherapy; to expand the comparison to an additional institution, patients treated with similar NCRT at Stanford University were included.

METHODS AND MATERIALS

Sixty-nine patients with cT3-4N0-2M0 rectal adenocarcinoma enrolled on the Washington University in St. Louis phase 2 study of nTNT were included for analysis. Patients treated at the same institution with conventional NCRT and adjuvant FOLFOX were matched for exact cTNM stage. Forty-one patients treated with NCRT at Stanford University were included in a second analysis. Kaplan-Meier analysis with log-rank test was used to compare local control, distant metastasis-free survival, disease-free survival, and overall survival.

RESULTS

Median follow-up was 49 and 54 months for nTNT and NCRT, respectively. Pathologic complete response and T-downstaging rates were 28% versus 16% (P=.21) and 75% versus 41% (P<.001) in the nTNT and NCRT cohorts, respectively. Three-year disease-free survival (85% vs 68%, P=.032) was significantly better in the nTNT group. Actuarial 3-year local control (92% vs 96%, P=.36) and overall survival (96% vs 88%, P=.67) were similar. The Stanford cohort had significantly lower clinical stage. After controlling for clinical stage, age, tumor location, institution, and number of chemotherapy cycles, nTNT treatment remained significantly associated with lower risk of recurrence (P=.006).

CONCLUSIONS

Patients treated with nTNT had higher T-downstaging and superior distant metastasis-free survival and disease-free survival compared with conventional NCRT when matched for tumor location and exact cTNM stage. Near total neoadjuvant therapy remained a significant multivariate predictor for improved outcome when including patients treated with NCRT at another institution.