Le statut KRAS n’influence pas l’efficacité de l’oxaliplatine ou de l’irinotécan, en association au bévacizumab, dans le traitement de première ligne du cancer colorectal métastatique

Abstract

The identification of RAS status (KRAS and NRAS) has changed the management of metastatic colorectal cancer (mCRC). The impact of the RAS mutation on cytotoxic chemotherapy efficacy has not yet been determined. Nevertheless, several retrospective studies suggest a greater efficacy of oxaliplatin in mCRC with KRAS mutation. We analyzed retrospectively the progression free survival (PFS) and overall survival (OS) in 216patients with mCRC receiving first line treatment between 2008and 2010according to KRAS status and chemotherapy regimen used (oxaliplatin- or irinotecan-based, in association with fluoropyrimidine and bevacizumab). In KRAS mutated tumors, median OS was 23.4months with oxaliplatin-based regimen, and 23.6months with irinotecan-based regimen, with no significant difference (HR 1.30; 95% CI 0.81-2.09; P=0.27). In KRAS wild-type tumors, median OS was 30.3months with oxaliplatin-based regimen, and 25.4months with irinotecan-based regimen, with no significant difference (HR 0.81; 95% CI 0.52-1.24; P=0.33). Similarly, KRAS mutational status had no significant effect on efficacy of oxaliplatin or irinotecan regarding PFS. In this retrospective study, KRAS mutational status does not influence the efficacy of first line cytotoxic chemotherapy in association with bevacizumab.