KRAS as a predictor of poor prognosis and benefit from postoperative FOLFOX chemotherapy in patients with stage II and III colorectal cancer

Document Type

Journal Article

Publication Date

8-1-2015

Journal

Molecular Oncology

Volume

9

Issue

7

DOI

10.1016/j.molonc.2015.03.006

Keywords

Adjuvant chemotherapy; Colorectal cancer; FOLFOX; KRAS

Abstract

© 2015 Federation of European Biochemical Societies. 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.

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