Association Between Adjuvant Chemotherapy and Overall Survival in Patients With Rectal Cancer and Pathological Complete Response After Neoadjuvant Chemotherapy and Resection
Open Access
- 30 June 2018
- journal article
- research article
- Published by American Medical Association (AMA) in JAMA Oncology
- Vol. 4 (7), 930-937
- https://doi.org/10.1001/jamaoncol.2017.5597
Abstract
IMPORTANCE Although American guidelines recommend use of adjuvant chemotherapy in patients with locally advanced rectal cancer, individuals who achieve a pathological complete response (pCR) following neoadjuvant chemoradiotherapy are less likely to receive adjuvant treatment than incomplete responders. The association and resection of adjuvant chemotherapy with survival in patients with pCR is unclear. OBJECTIVE To determine whether patients with locally advanced rectal cancer who achieve pCR after neoadjuvant chemoradiation therapy and resection benefit from the administration of adjuvant chemotherapy. DESIGN, SETTING, AND PARTICIPANTS This retrospective propensity score-matched cohort study identified patients with locally advanced rectal cancer from the National Cancer Database from 2006 through 2012. We selected patients with nonmetastatic invasive rectal cancer who achieved pCR after neoadjuvant chemoradiation therapy and resection. EXPOSURES We matched patients who received adjuvant chemotherapy to patients who did not receive adjuvant treatment in a 1: 1 ratio. We separately matched subgroups of patients with node-positive disease before treatment and node-negative disease before treatment to investigate for effect modification by pretreatment nodal status. MAIN OUTCOME AND MEASURES We compared overall survival between groups using Kaplan-Meier survival methods and Cox proportional hazards models. RESULTS We identified 2455 patients (mean age, 59.5 years; 59.8% men) with rectal cancer with pCR after neoadjuvant chemoradiation therapy and resection. We matched 667 patients with pCR who received adjuvant chemotherapy and at least 8 weeks of follow-up after surgery to patients with pCR who did not receive adjuvant treatment. Over a median follow-up of 3.1 years (interquartile range, 1.94-4.40 years), patients treated with adjuvant chemotherapy demonstrated better overall survival than those who did not receive adjuvant treatment (hazard ratio, 0.44; 95% CI, 0.28-0.70). When stratified by pretreatment nodal status, only those patients with pretreatment node-positive disease exhibited improved overall survival with administration of adjuvant chemotherapy (hazard ratio, 0.24; 95% CI, 0.10-0.58). CONCLUSIONS AND RELEVANCE The administration of adjuvant chemotherapy in patients with rectal cancer with pCR is associated with improved overall survival, particularly in patients with pretreatment node-positive disease. Although this study suggests a beneficial effect of adjuvant treatment on survival in patients with pCR, these results are limited by the presence of potential unmeasured confounding in this nonrandomized study. (C) 2018 American Medical Association. All rights reserved.Keywords
This publication has 58 references indexed in Scilit:
- Preoperative chemoradiotherapy and postoperative chemotherapy with fluorouracil and oxaliplatin versus fluorouracil alone in locally advanced rectal cancer: initial results of the German CAO/ARO/AIO-04 randomised phase 3 trialThe Lancet Oncology, 2012
- Quality indicators for colorectal cancer surgery and care according to patient-, tumor-, and hospital-related factorsBMC Cancer, 2012
- A Tutorial and Case Study in Propensity Score Analysis: An Application to Estimating the Effect of In-Hospital Smoking Cessation Counseling on MortalityMultivariate Behavioral Research, 2011
- Does adjuvant fluoropyrimidine-based chemotherapy provide a benefit for patients with resected rectal cancer who have already received neoadjuvant radiochemotherapy? A systematic review of randomised trialsAnnals of Oncology, 2010
- Bevacizumab Beyond First Progression Is Associated With Prolonged Overall Survival in Metastatic Colorectal Cancer: Results From a Large Observational Cohort Study (BRiTE)Journal of Clinical Oncology, 2008
- Bevacizumab in Combination With Oxaliplatin, Fluorouracil, and Leucovorin (FOLFOX4) for Previously Treated Metastatic Colorectal Cancer: Results From the Eastern Cooperative Oncology Group Study E3200Journal of Clinical Oncology, 2007
- Combined Analysis of Efficacy: The Addition of Bevacizumab to Fluorouracil/Leucovorin Improves Survival for Patients With Metastatic Colorectal CancerJournal of Clinical Oncology, 2005
- Efficacy of adjuvant fluorouracil and leucovorin in stage B2 and C colon cancerSeminars in Oncology, 2001
- Efficacy of adjuvant fluorouracil and leucovorin in stage B2 and C colon cancerSeminars in Oncology, 2001
- Levamisole and Fluorouracil for Adjuvant Therapy of Resected Colon CarcinomaNew England Journal of Medicine, 1990