Safety results of a phase III randomized trial of adjuvant treatment with 5- fluorouracil and folinic acid with or without irinotecan, in Dukes B2 and C colon cancer
4053 Background: The aim of our phase III study was to compare the effectiveness and the toxicity profile of 5-Fluorouracil (5- FU) + folinic acid (FA) + irinotecan (CPT-11) as adjuvant chemotherapy for resectable colon cancer (Dukes B2 and C) to that of 5-FU + FA which was considered the standard treatment. Since patients are still on follow-up regarding the primary endpoint, only safety results will be presented. Methods: Eligible patients received either 5-FU (450 mg/m2 bolus) + FA (200 mg/m2, 120 min infusion) + CPT- 11 (80 mg/m2, 90 min infusion) given 4 weeks on, two weeks off for a total of 6 treatment cycles (Arm A) or 5-FU (500 mg/m2 bolus) + FA (200 mg/m2, 120 min infusion) given 6 weeks on, two weeks off for a total of 4 treatment cycles (Arm B). Results: From January 1999 to September 2004, 910 patients (pts) were enrolled in this multi-center phase III trial. Safety data are available for 826 of the 910 pts, (415 in arm A and 411 in arm B). The total number of chemotherapy courses delivered was 8,906 (92%) in arm A and 8,775 (91%) in arm B, with median courses per patient 24 in both groups. Among patients who received treatment as randomized (403 in arm A and 398 in arm B), treatment was completed in 342 pts (82%) in arm A and in 341 pts (83%) in arm B. The number of patients who discontinued the treatment was 61 (15%) in arm A and 57 (14%) in arm B. Hospitalizations because of toxic effects happened in 37 pts (9%) in arm A and in 45 pts (11%) in arm B. Three deaths occurred in both arms. Use of G-CSF was more common in arm A (94 pts, 23%) than in arm B (38 pts, 9.5%) (p< 0.001). Significantly higher grade 3/4 neutropenia was observed in group A (11% in arm A and 3% in arm B, p< 0.001). Severe diarrhea was also frequently reported in both groups. Conclusions: These data show that both regimens have comparable and manageable toxicity profiles as adjuvant treatment in colon cancer. Severe neutropenia was more often seen in arm A. No significant financial relationships to disclose.