Combination of Irinotecan, Oxaliplatin and 5-Fluorouracil as a Rechallenge Regimen for Heavily Pretreated Metastatic Colorectal Cancer Patients.

Purpose: Our objective was to evaluate the benefit of re-exposing patients with refractory metastatic colorectal cancer (mCRC) to a combination of oxaliplatin, irinotecan and 5-fluorouracil treatment.

Methods: We retrospectively analysed patients with mCRC who received a combination of oxaliplatin, irinotecan and fluorouracil as a rechallenge regimen after progressing on the same drugs. Both FOLFOXIRI and FOLFIRINOX were used. Toxicity was evaluated for each treatment cycle, and survival analysis was performed using the Kaplan-Meier method.

Results: A total of 21 patients who were treated between January 2011 and December 2013 were selected for this study. Most of the patients (95.2%) had an ECOG status of 0-1. The median age at diagnosis was 52.1 years (range 36-77 years), and 14 (66.6%) patients had wild-type KRAS. Thirteen patients received FOLFIRINOX, and eight received FOLFOXIRI. Most patients had previously received at least three regimens, with 80% receiving anti-VEGF and 66% anti-EGFR antibodies. The response rate was 38%, and 24% patients had stable disease. The median time to disease progression was 4.0 months (range 1.0-9.1 months), and the median overall survival duration was 8.6 months (range 6.3-11.5 months). Most patients required dose adjustment and treatment delays. One patient experienced grade 5 neutropenic sepsis.

Conclusions: Both FOLFIRINOX and FOLFOXIRI are active and potentially feasible rechallenge treatment options for heavily pretreated patients with good performance status. With dose reduction and close monitoring for toxicity, the risk of serious adverse events can be minimised.