Journal - Zhonghua yi xue za zhi (China )

Abstract :

OBJECTIVE: To investigate the viral oncogene homolog B1 (BRAF) mutation frequency in serrated colorectal adenocarcinoma (Sca), and to verify the existence of a new serrated pathway indirectly. METHODS: 75 paraffin-embedded tissue samples, including 15 cases of Sca, 20 cases of traditional serrated adenoma (TSA), 20 cases of non-serrated adenocarcinoma (NS-ca), and 20 cases of villous adenoma, were reviewed. Nest-PCR was used to amplify the exon 15 fragment of BRAF gene. RFLP assay was used to detect the BRAF V600E mutation. The positive samples were verified by direct sequencing. RESULTS: Four of the 11 successfully amplified Sca specimens (4/11, 36.4%), and 4 of the 15 TSA samples (4/15, 26.7%) harbored BRAF V600E mutation. However, no BRAF V600E mutation was found in the 14 NS-ca samples and the 11 villous adenoma specimens. The BRAF V600E mutation frequencies of the villous adenoma group and NS-ca group were significantly lower than those of the TSA group and Sca group (P = 0.0084); however, there was no statistical difference in the frequency of BRAF V600E mutation between the Sca and TSA groups (P > 0.05). CONCLUSION: BRAF V600E mutation frequency is significantly higher in the Sca and TSA patients than in the NS-ca and villous adenoma patients. There is actually a new serrated neoplasia pathway different from the traditional adenoma-carcinoma carcinogenesis pathway.