First-line therapy for metastatic colorectal carcinoma: modified FOLFOX4 or FOLFIRI-bevacizumab

The aim of this study was to compare the efficacy and toxicity of modified (m) FOLFOX4 (folinic acid, 5-fluorouracil [5-FU], and oxaliplatin) vs. FOLFIRI-B (folinic acid, 5-FU, irinotecan, and bevacizumab) as first-line treatment of metastatic colorectal carcinoma (MCRC).

The medical records of 89 MCRC patients treated with either mFOLFOX4 (group 1) or FOLFIRI-B (group 2) as first-line chemotherapy were evaluated retrospectively.

Complete (CR) plus partial response (PR) were seen in 18 (36.7%) vs. 13 (32.5%) patients in the mFOLFOX4 vs. FOLFIRI-B, respectively (p=0.67). Median progression-free survival (PFS) was 9 months (95% CI 7.2- 9.5) vs. 10 months (95% CI 7.6-12.3) in group 1 vs. group 2, respectively (p=0.30). Median overall survival (OS) was 22 months (95% CI 17.6-26.3) and 19 months (95% CI 13-24.9) in group 1 and 2, respectively (p=0.32). There was no statistically significant difference in grade 3-4 hematological toxicity between the groups, but grade 3-4 grade weakness, diarrhea, nausea and vomiting was observed more frequently in the FOLFIRI-B patients (p=0.03, p=0.01, p=0.05, respectively).

Our data suggest that mFOLFOX4 and FOLFIRI-B are equally effective as first-line chemotherapy in MCRC patients. This may partially be explained by the fact that almost 50% of those receiving FOLFOX in the first-line received FOLFIRI-B in the second-gline, an observation suggesting that bevacizumab in the second line may be as effective as in the first line.