Mutational analysis of BRCA1 and BRCA2 in northwest Chinese breast cancer patients.

Abstract

BackgroundBRCA1 and BRCA2 are the most well-known susceptibility genes in breast cancer, indicating high-risk breast cancer families and influencing both treatment options. However, data of BRCA mutation in Chinese breast cancer population was limited. Here we explored the BRCA1/2 mutation status and analyzed their clinicopathological relationships among breast cancer patients with high hereditary risk in northwest China.MethodsBreast cancer patients admitted to Xijing Hospital, between November 2015 and May 2016, with high hereditary risk were recruited. Fresh peripheral venous blood samples were collected for BRCA1/2 gene screening. Risk factors for BRCA1/2 mutations were studied via single-factor analysis and multivariable logistic analysis. Furthermore, we reviewed the literature and discussed the possible mechanism of the mutant genome types.ResultsEighty-two patients were enrolled in the study. Twenty (24.4%) of them were found with BRCA1/2 mutation, including 8 BRCA1 mutation and 13 BRCA2 mutation. BRCA1 and BRCA2 co-mutation was observed in only one case. The mutant genome types included pathogenic variant (4/82), potential pathogenic variant (4/82), beneficial mutations (8/82), and chemotherapy sensitivity-related mutations (5/82). Prognosis-related mutations were enriched in BRCA2 gene, while drug-sensitive related mutations were always observed in BRCA1 gene. Multiple logistic analysis showed that HER2 [odds ratio (OR) 4.58; 95% confidence interval (CI), 1.182–17.74; P=0.028) might be independent factor for BRCA1/2 mutation.ConclusionsThe incidence and feature of BRCA1/2 mutation in our center was similar to that in other regions. HER2 expression was independent factor for BRCA1 and BRCA2 mutation. BRCA2 T/-, BRCA2 A/-, BRCA2 G/- and BRCA2 C/-mutation subtypes might be potential harmful mutations for Chinese breast cancer population.