FOLFOX regimen improved five-year survival in metastatic colorectal cancer

Five-year follow-up data from a trial involving patients with metastatic colorectal cancer indicated that the combination regimen FOLFOX resulted in better five-year survival rates than other regimens.

“Despite progress in the treatment of [metastatic colorectal cancer], tumors are heterogeneous,” the investigators wrote. “A substantial minority of patients still fare poorly and have minimal response to treatment and rapid disease progression that culminates in death within a year of diagnosis.” In this study, 1,691 patients were randomly assigned to one of seven fluorouracil-, oxaliplatin- or irinotecan-containing regimens.

The five-year survival rate was 9.8% with FOLFOX; this was better than irinotecan plus bolus fluorouracil and leucovorin (3.7%; P=.04), as well as bolus irinotecan/oxaliplatin (5.1%; P=.128). OS for FOLFOX was 20.2 months, with a time to progression of 8.9 months. For irinotecan plus bolus fluorouracil and leucovorin, OS was 14.6 months and time to progression was 6.1 months (P<.001 for both). For bolus irinotecan/oxaliplatin, OS was 17.3 months and time to progression was 6.7 months (P<3.001 for both).

Treatment with the FOLFOX regimen was the strongest prognostic predictor of improved outcome, and the investigators noted that the other explored prognostic factors “seem to add little to clinical treatment decision-making.” After FOLFOX treatment, performance status and the number of metastatic sites were most strongly correlated with OS.

“The 9.8% five-year survival observed for FOLFOX–treated patients in this trial sets a new benchmark in clinical trials for patients who have metastatic colorectal cancer,” the researchers wrote, adding that this compares with previously reported rates of 1% for five-year survival.

J Clin Oncol. 2008;doi:10.1200/JCO.2008.17.7147.