Age, gender, and performance status effects on efficacy of 3 versus 6 months of adjuvant oxaliplatin and fluoropyrimidine chemotherapy for stage III colon cancer: Phase III ACHIEVE trial as part of the IDEA collaboration.
731 Background: ACHIEVE, a part of the IDEA collaboration, was a multicenter trial randomizing patients with stage III resected colon cancer to either 3 versus 6 months of mFOLFOX6/CAPOX. The primary endpoint was disease-free survival (DFS). We previously reported that the hazard ratios (HRs) of 3 versus 6 months duration in this study according to risk stage (low-risk [T1-3 and N1] or high-risk [T4 or N2]) and regimen (mFOLFOX6 or CAPOX) as well as in overall population were consistent with those observed in the whole IDEA. Methods: ACHIEVE enrolled 1313 patients in Japan between August 2012 and June 2014, out of whom 1291 pts were analyzed for efficacy analysis. As of June 2017, 291 DFS events were observed with a median follow-up time of 39 months. The HR of DFS in the overall population was 0.95 (0.76—1.20) with a 3-year DFS of 80% in 3 months arm and 78% in 6 months arm. In the current study, we investigated subgroup analyses for DFS including age, gender, and ECOG performance status (PS). Results: Outcomes of subgroup analyses are summarized in the Table. With regard to HRs and upper bound on the confidence intervals, the trend of 3 months arm being slightly inferior to 6 months arm in patients with an age of ≥70, female gender, and an ECOG PS of 1; however, there was no evidence of significant interaction across treatment duration and the subgroups. Conclusions: The treatment duration effect did not depend on age, gender, and ECOG PS. Further results according to risk stage and regimen will be presented. Clinical trial information: UMIN 000008543. [Table: see text]