KRAS and BRAF mutations in prostate carcinomas of Chinese patients

Aberrance in the RAS/RAF/MEK/MAPK pathway is reportedly important in many tumor types, including prostate carcinoma. Continuous activation of the pathway can be caused by mutations of upstream targets such as KRAS and BRAF. However, rates of KRAS and BRAF mutations in prostate carcinoma are reported to vary in different populations. To date, there has been no such report in Chinese patients. In this study, we examined 121 samples of prostate carcinoma in Chinese subjects for mutations at codons 12 and 13 of KRAS and codon 600 of BRAF by means of the mutant-enriched polymerase chain reaction-coupled sequencing method. The identified KRAS and BRAF mutations were analyzed for association with tumor differentiation and clinical stage. The result showed that KRAS mutations were detected in 9.1% (11 of 121) of prostate carcinomas, while no BRAF mutation was found in any case studied. No association was found between KRAS mutation and clinicopathological characteristics of the tumors. Our study suggests that mutations of KRAS, not BRAF, may play a role in the pathogenesis of prostate carcinoma in Chinese patients.