Efficacy of FOLFOXIRI versus XELOXIRI plus bevacizumab in the treatment of metastatic colorectal cancer.

backgroundChemotherapy with capecitabine combined with leucovorin, oxaliplatin, and irinotecan plus bevacizumab (XELOXIRI-Bev) or fluorouracil, leucovorin, oxaliplatin, and irinotecan plus bevacizumab (FOLFOXIRI-Bev), is recently introduced as first-line treatment for metastatic colorectal cancer (mCRC). The comparison between the two strategies above in clinical efficacy has not been assessed.

methodsWe retrospectively reviewed 138 patients with untreated metastatic colorectal cancer to receive either FOLFOXIR-Bev (group 1) or XELOXIRI-Bev (group 2). Up to 12 cycles of treatment were administered, followed by fluorouracil plus bevacizumab until disease progression. The primary end point was progression-free survival.

resultsThe mean progression-free survival was 13.5 months in the group 1, as compared with 10.4 months in the group 2 (hazard ratio for progression, 0.3; 95% confidence interval [CI], 0.12 to 0.83; P = 0.032). The objective response rate was 71% in the group 1 and 52.2% in the group 2 (P = 0.006). Overall survival was not found significant difference between the two groups (group 1 vs. 2; 31.3 vs. 24.6 months; hazard ratio for death, 0.6; 95% CI, 0.29 to 1.15; P = 0.115). The incidences of grade 3 or 4 neurotoxicity, stomatitis, diarrhea, and neutropenia were significantly higher in the group 1.

conclusionFOLFOXIR-Bev, as compared with XELOXIRI-Bev, improved the outcomes in patients with mCRC, but increased the incidence of some adverse events.