Purpose: The KRAS gene frequently mutates in colorectal cancer (CRC). Here we investigated the prognostic and predictive role of KRAS mutation in patients with stage II or III CRC.
Experimental design: A consecutive cohort of patients with stage II or III CRC from a single center database was studied. The association between KRAS status, adjuvant FOLFOX therapy, and 3-year disease-free survival (3-y DFS) was analyzed.
Results: Of our 433 patients, 166 (38.3%) exhibited the KRAS mutation. Among the 190 patients who did not receive adjuvant therapy, those with KRAS mutation tumors had a worse 3-y DFS (hazard ratio [HR], 1.924; 95% confidence interval [CI], 1.078-3.435; P = 0.027). Among patients who received adjuvant chemotherapy, KRAS mutation was not correlated with worse 3-y DFS (HR, 1.083; 95% CI, 0.618-1.899; P = 0.781). Adjuvant chemotherapy improved 3-y DFS only among patients with KRAS mutant tumors (78.0% vs 69.2%) on multivariate analysis adjusted for age, stage, grade, site, vessel invasion, and carcinoembryonic antigen level (HR, 0.454; 95% CI, 0.229-0.901; P = 0.024). In contrast, there was no benefit of adjuvant chemotherapy in the KRAS wild-type group (84.3% vs 82.0%).
Conclusions: KRAS mutation indicates poor prognosis. FOLFOX adjuvant chemotherapy benefits patients with stage II or III colorectal cancer with KRAS mutant tumors and is worth further investigation.
Keywords: Adjuvant chemotherapy; Colorectal cancer; FOLFOX; KRAS.
Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.