Abstract
Purpose : Reduction of adjuvant treatment duration may decrease toxicities without loss of efficacy in stage III colon cancer. This could offer clear advantages to patients and health care providers. Methods : In International Duration Evaluation of Adjuvant Chemotherapy (IDEA) France, as part of the IDEA international collaboration, patient with colon cancer patients were randomly assigned to 3 and 6 months of modified FOLFOX6 (mFOLFOX6: infusional fluorouracil, leucovorin, and oxaliplatin) or capecitabine plus oxaliplatin (CAPOX) by physician choice. The primary end point was disease-free survival (DFS), and analyses were descriptive. Results : A total of 2,010 eligible patients received either 3 or 6 months of chemotherapy (modified intention-to-treat population); 2,000 (99%) had stage III colon cancer (N1: 75%, N2: 25%); 1,809 (90%) received mFOLFOX6, and 201 (10%) received CAPOX. The median age was 64 years, and the median follow-up time was 4.3 years. Overall, 94% (3 months) and 78% (6 months) of patients completed treatment (fluoropyrimidines ± oxaliplatin). Maximal grade 2 and 3 neuropathy rates were 28% and 8% in the 3-month arm and 41% and 25% in the 6-month arm ( P < .001). Final rates of residual neuropathy greater than grade 1 were 3% in the 3-month arm and 7% in the 6-month arm ( P < .001). There were 578 DFS events: 314 and 264 in the 3- and 6-month arms, respectively. The 3-year DFS rates were 72% and 76% in the 3- and 6-month arms, respectively (hazard ratio [HR], 1.24; 95% CI, 1.05 to 1.46; P = .0112). In the 3 and 6-month arms, respectively, for patients who received mFOLFOX6, the 3-year DFS rates were 72% and 76% (HR, 1.27; 95% CI, 1.07 to 1.51); for the T4 and/or N2 population, they were 58% and 66% (HR, 1.44; 95% CI, 1.14 to 1.82); and for the T1-3N1 population, they were 81% and 83% (HR, 1.15; 95% CI, 0.89 to 1.49). Conclusion : IDEA France, in which 90% of patients received mFOLFOX6, shows superiority of 6 months of adjuvant chemotherapy compared with 3 months, especially in the T4 and/or N2 subgroups. These results should be considered alongside the international IDEA collaboration data.