Late toxicities and clinical outcome at 5 years of the ACCORD 12/0405-PRODIGE 02 trial comparing two neoadjuvant chemoradiotherapy regimens for intermediate-risk rectal cancer.

Abstract

Outcome of intermediate risk rectal cancer may be improved by the addition of oxaliplatin during 5-fluoruracil concomitant neoadjuvant chemoradiotherapy. The purpose of this study is to analyze the main clinical results of the ACCORD12 trial (NCT00227747) in rectal cancer after 5 years of follow-up. Inclusion criteria were as follows: rectal adenocarcinoma accessible to digital examination staged T3-T4 Nx M0 (or T2 Nx distal anterior rectum). Two neoadjuvant chemoradiotherapy regimens were randomized: CAP45 (RT 45 Gy + capecitabine) and CAPOX50 (RT 50 Gy + capecitabine and oxaliplatin). Main end point was sterilization of the operative specimen. Acute and late toxicities were prospectively analyzed with dedicated questionnaires. Between November 2005 and July 2008, 598 patients were included in the trial. After a median follow-up of 60.2 months, there was no difference between treatment arms in multivariate analysis either for disease-free survival or overall survival (OS) [P = 0.9, hazard ratio (HR)=1.02; 95% confidence interval (CI), 0.76-1.36 and P = 0.3, HR = 0.87; 95% CI, 0.66-1.15, respectively]. There was also no difference of local control in univariate analysis (P = 0.7, HR = 0.92; 95% CI, 0.51-1.66). Late toxicities were acceptable with 1.6% G3 anal incontinence, and <1% G3 diarrhea, G3 rectal bleeding, G3 stenosis, G3-4 pain, G3 urinary incontinence, G3 urinary retention and G3 skeletal toxicity. There was a slight increase of erectile dysfunction over time with a 63% rate of erectile dysfunction at 5 years. There was no significant statistical difference for these toxicities between treatment arms. The CAPOX50 regimen did not improve local control, disease-free survival and overall survival in the ACCORD12 trial. Late toxicities did not differ between treatment arms.