A systematic review of FOLFOXIRI chemotherapy for the first-line treatment of metastatic colorectal cancer: improved efficacy at the cost of increased toxicity

Aim The simultaneous administration of irinotecan, 5-fluorouracil, folinic acid and oxaliplatin (FOLFOXIRI) has been compared with standard 5-fluorouracil, folinic acid and irinotecan (FOLFIRI) in randomized trials in metastatic colorectal cancer patients. A superior efficacy of FOLFOXIRI has been reported by some authors, but others have failed to show any differences and do not recommend its use because of greater cost and toxicity. We performed a systematic review of the literature to analyse efficacy and toxicity of FOLFOXIRI. Method Odds ratios (OR) with 95% confidence intervals (CI) were used to analyse dichotomous variables. Hazard ratios (HR) for progression and death were combined with an inverse variance method based on logarithmic conversion. A fixed-effect model and Mantel-Haenszel's method were used. Heterogeneity was tested with Cochrane's Q test and I-2 test. Results A significant increase in response rate (OR 2.04; P < 0.01) was associated with treatment by FOLFOXIRI and a benefit was also shown by the HR for progression (HR 0.72; P < 0.01) and death (HR 0.71; P < 0.01). Analysis for toxicity found a significant increase associated with FOLFOXIRI except for anaemia, fatigue and febrile neutropenia. Conclusion FOLFOXIRI confers significant benefit in progression-free survival, survival, response and R0 resection rates but is more toxic compared with FOLFIRI.