Correlation between KRAS mutations and clinicopathologic features in colorectal carcinomas

Abstract

To investigate mutations of KRAS gene and clinicopathological characteristics of colorectal carcinomas (CRC) in Chinese. Tumor cells were collected by microdissection from paraffin-embedded tumor specimens and adjacent normal colon tissues from 167 CRC patients. Genomic DNA was extracted and mutations of KRAS gene (codons 12 and 13) were detected by scorpions amplification refractory mutation system (Scorpions ARMS). KRAS mutations were identified in 66 patients (39.5%), including G13D (21 cases, 12.6%), G12D (15 cases, 9.0%), G12V (13 cases, 7.8%), G12C (6 cases, 3.6%), G12A (5 cases, 3.0%), G12S (4 cases, 2.4%) and G12R (2 cases, 1.2%). Female patients had a higher KRAS mutation rate than male (50.0%, 29/58 vs.33.9%, 37/109, P < 0.05). However, KRAS mutations did not correlate with the patient age, tumor sites, histological types and grades (P > 0.05). Additionally, 7 of 18 patients with metastatic CRC had KRAS gene mutations. Overall, KRAS gene mutation was identified in 59 patients among 149 primary CRC (39.6%). There was no significant difference in KRAS mutation between primary and metastatic tumors (P > 0.05). The detection rate of KRAS mutation is higher in female CRC patients than the males. The presence of KRAS mutation does not significantly correlate with the patients' age, tumor site, differentiation grades and histological types. There was no significant difference in KRAS mutation between the primary and metastatic tumors.