Tolerability study of adjuvant modified FOLFOX6 treatment in curatively resected stage II/III colon cancer (JFMC41-1001-C2: JOIN trial).

530 Background: Adjuvant FOLFOX is a widely accepted standard regimen for resected colon cancer. The incidence of grade ≥ 3 peripheral sensory neuropathy (PSN) was 12.4% and 5.7% in Western MOSAIC and Eastern MASCOT (outside Japan) trials, while that of grade ≥ 3 allergic reactions (AR) was 2.9% and 3.1%, respectively. JOIN Trial investigated the tolerability of modified FOLFOX6 (mFOLFOX6) in Japanese patients (UMIN ID: 000004443). Methods: Twelve cycles of mFOLFOX6 were given to patients fitting the following criteria, which were the same as those of MOSAIC: stage II/III resected colon cancer, PS of 0-1, 20 years or older, starting FOLFOX within 7 weeks of surgery, and adequate organ function. The primary endpoint was the incidence of PSN persisting for at least 8 days that interfered with daily activities and that of grade ≥ 3 AR. Target sample size was 800, assuming the expected incidence of grade ≥ 3 PSN and grade ≥ 3 AR would be 12.0% and 3.0%, and the two-sided 95% confidence interval (CI) would not...