Outcome of second-line treatment after first-line chemotherapy with the GONO FOLFOXIRI regimen

PurposeFOLFOXIRI demonstrated higher efficacy compared to 5-fluorouracil, leucovorin, irinotecan (FOLFIRI) as first-line treatment of metastatic colorectal cancer. We evaluated the outcome of second-line treatments among 196 patients treated with first-line FOLFOXIRI in three consecutive trials conducted by the Gruppo Oncologico Nord Ovest group.Patients and MethodsOne hundred seventy-two of 196 patients so far progressed and 136 (79%) received second-line therapies: 32 (24%) were rechallenged with FOLFOXIRI, 52 (38%) were treated with irinotecan- or oxaliplatin-based doublets, and 52 (38%) received fluoropyrimidine plus mytomicin C or single-agent chemotherapy. Only 10 patients received bevacizumab (3) or cetuximab (7) with chemotherapy. Activity and efficacy data were collected and subgroup analyses were performed according to the regimen administered.ResultsOverall response rate (RR) was 23%; median progression-free survival (PFS) and overall survival (OS) were 5.9 and 13.2 months, respectively. At an exploratory subgroup analysis, retreatment with FOLFOXIRI was associated with longer PFS (8.2 versus 6.3 months; P = .003, hazard ratio [HR] = 0.61) and OS (19.3 versus 14.0 months; P = .02, HR = 0.57) compared with doublets; single-agent chemotherapy or fluoropyrimidine plus mytomicin C was significantly lower in terms of RR (8%), PFS (3.0 months), and OS (8.7 months) compared with FOLFOXIRI or doublets.ConclusionsFirst-line FOLFOXIRI does not impair the efficacy of second-line treatments. In some patients rechallenge with FOLFOXIRI may represent a valid option, although potential imbalances in prognostic factors due to better patient selection should be considered.