ABSTRACT
Objective To investigate the relationship between KRAS,NRAS and BRAF gene mutations and clinicopathological parameters in patients with colorectal carcinoma (CRC).Methods By using TagMan real-time PCR method KRAS/NRAS/BRAF hotspot mutations were detected in 260 cases of CRC.The associations between KRAS/NRAS/BRAF mutation status and clinical pathological characteristics were analysed in different groups divided by gender,age,tumor size,tumor differentiation.Results (1) The KRAS hotspot mutations were G12D,G12A,G12R,G12C,G12V,G12S in codon 12 and G13 C,G13D in codon 13.They were identified in 43.1％ CRC.KRAS mutation rate was higher in females than in males (P =0.05) and the mutation rate in patients ≥ 60 years was significantly higher than that in patients ＜ 60 years(P =0.008).The incidence of metastasis and mortality were higher in KRAS mutant than in KRAS wild type (P =0.004,P =0.037).(2)The NRAS hotspot mutations were in codon1 2,13 and 61.They were identified in 4.6％ CRC.NRAS mutation rate was significantly higher in patients ≥ 60 years and well-differentiated tumors (P =0.032,P =0.042).(3) The mutation rate of BRAF V600E in CRC patients was 4.6％.BRAF V600E mutation rate was significantly higher in patients ≥60 years,with distant metastases and tumors ＞ 5 cm (P =0.032,P =0.026,P =0.038).The incidence of metastasis and rucurrence and mortality were higher in BRAF mutant (P =0.030,P =0.002,P =0.007).Conclusions In CRC patients,KRAS mutations correlate with demographic factors,metastasis and mortality,NRAS mutations correlate with age and tumor differentiation,while BRAF mutation correlate with age,tumor size,metastasis,recurrence and mortality.