469PD - Phase III trial of 24 weeks vs. 48 weeks capecitabine adjuvant chemotherapy for patients with stage III colon cancer: Final results of JFMC37-0801

Abstract

JFMC37-0801 study was planned to offer superiority of 48 weeks treatment of capecitabine adjuvant chemotherapy to 24 weeks conventional treatment with respect to the primary endpoint of disease free survival (DFS) in patients with stage III colon and rectosigmoid cancer. Here, we report the final results of this study. Patients with curatively resected stage III colon and rectosigmoid cancer (PS, 0 to 1; age, 20 to 79 years; no other therapy) were randomly assigned to receive capecitabine (1,250 mg/m2/day) for 14 out of 21 days for 24 weeks, 8 courses (Control (C) arm) or for 48 weeks, 16 courses (Study (S) arm). The primary endpoint was the DFS, and the secondary endpoints were overall survival (OS) and relapse free survival (RFS). Patient information was fixed in March 2016. At the time of this final analysis, median follow-up was 60 months with 434 DFS events out of 1304 (C: 654, S: 650) pts. The 3-year and 5-year DFS for the primary endpoint was 75.3%, 68.7% in the S arm and 70.0%, 65.3% in the C arm, respectively (p = 0.068, HR = 0.866, 95%CI: 0.717-1.046). The 5-year OS was 87.6% in the S arm and 83.2% in the C arm (p = 0.0159, HR = 0.737, 95%CI: 0.557-0.975). The 5-year RFS was 74.1% in the S arm and 69.3% in the C arm (p = 0.0207, HR = 0.808, 95%CI: 0.658-0.992). Overall grade 3-4 adverse events of S arm were comparable with those of C arm except increasing hand-foot syndrome. DFS superiority in 48 weeks treatment of capecitabine adjuvant chemotherapy was not demonstrated in patients with stage III colon cancer. However, p-values of OS and RFS comparing 48 weeks treatment with 24 weeks treatment were less than 0.025. Thus, with regard to the optimal duration of adjuvant chemotherapy for stage III colon cancer, further investigation was considered to be needed.