Clinical Predictors for KRAS Codon 13 Mutations in Patients With Colorectal Cancer

This study sought to clarify sex differences in KRAS mutations and clinical predictors of KRAS 13 codon mutations.

Sex differences in KRAS mutations and predictors for KRAS codon 13 mutations in colorectal cancer (CRC) are unclear.

Between October 2007 and May 2016, 328 patients underwent surgery for CRCs that were analyzed for KRAS mutations at a referral university hospital. Sex differences in the rates and distributions of KRAS mutations, and factors predictive of overall KRAS and KRAS codon 13 mutations were analyzed.

KRAS mutations were significantly more common in women than men patients (46.0% vs. 34.4%, P<0.033). However, no sex differences were detected for KRAS mutations by codon subtypes (P=0.592). The Gly13Asp (GGC>GAC) point mutation was identified only within codon 13 in both sexes. For right-sided CRC, KRAS mutations were twice as frequent in men as in women (univariate analysis; P=0.016, multivariate analysis; P=0.019). High-plasma cholesterol level was an independent predictive factor of KRAS codon 13 mutations by univariate (odds ratio, 1.013; 95% confidence interval, 1.003-1.023) and multivariate analysis (odds ratio, 1.011; 95% confidence interval, 1.001-1.021).

Sex differences may affect the presentation of KRAS mutations, as they were more frequently detected in women and in right-sided CRC in men. KRAS codon 13 mutations were significantly associated with high-plasma cholesterol. Further studies are needed on the clinical implications of this finding.