The Greek participitation to IDEA (International Duration Evaluation of Adjuvant Chemotherapy) study of 3 versus 6 months of adjuvant chemotherapy in stage III colon cancer: Patients’ characteristics and safety analysis.

Abstract

740 Background: The International Duration Evaluation of Adjuvant (IDEA) collaboration was established to prospectively analyze data from six randomized trials to assess whether a 3-month course of oxaliplatin/fluoropyrimidines (FU)-based adjuvant chemotherapy (CT) is non-inferior to the 6-month current standard treatment in stage III colon cancer (CC). The primary endpoint of IDEA was 3-year disease-free survival. The accrual goal for the Greek IDEA study was 1.000 patients. Methods: Greek IDEA randomized patients with stage III colon cancer between 3 months (arm A) and 6 months (arm B) of adjuvant CT with modified (m) FOLFOX6 or XELOX (depending on physician/patient choice). Toxicity was graded during treatment and follow-up using NCI-CTCAE v3.0. Results: From May 2009 to October 2015, 708 patients were randomized in Greek centers either to arm A (n = 354, 50%) or to arm B (n = 354, 50.%). 297 (41.9%) patients received mFOLFOX6 and 411 (58.%) XELOX. The median age was 67 years (20-75) and 579 (81.8%) of them had PS 0. The patients’ population was balanced for the major risk factor between the two arms: N1/N2 disease (68.1/31.9% vs. 68.9/31.1 for ARM A and B, respectively), obstruction (4.5% vs. 2.5 for ARM A and B, respectively) and perforation (5.1% vs. 6.2 for ARM A and B, respectively). Overall, 96.9% and 89.5% of patients completed 3 months (arm A) and 6 months (arm B) of CT, respectively. Median oxaliplatin dose was 505 mg/m2 in arm A and 738 mg/m2 in arm B. Toxicity profiles were comparable between the two arm and the two fluoropyrimidines backbones with a total incidence of Grade 3/4 adverse events 18.9/4.4% and 19.7/5.1% for mFOLFOX6 and XELOX, respectively. Grade 2/3-4 peripheral neuropathy during the study was similar between arm A (33.9/4%) and B (38.7/3.7%). Conclusions: Both mFOLFOX6 and XELOX were safe. More patients completed the scheduled treatment in the 3-arm schedule.