Characterization of mutations in BRCA1/2 and the relationship with clinic-pathological features of breast cancer in a hereditarily high-risk sample of chinese population

The database of BRCA1/2 mutations in Chinese population remains incomplete at present. Therefore, the present study aimed to report specific harmful BRCA1/2 mutations in the Chinese population and discuss the clinicopathological features in mutation carriers. BRCA1/2 germline mutation tests for 71 patients with breast cancer from a hereditarily high-risk Chinese population were performed using next-generation sequencing for identification of deleterious mutations. Furthermore, the clinicopathological features between BRCA1/2 mutation carriers and non-carriers were compared. A total of 13/71 (18.3%) patients carried a BRCA1 or BRCA2 mutation (7 BRCA1 and 6 BRCA2). The incidence of BRCA1/2 mutation in patients with bilateral breast cancer and patients with family history were 25, and 32.2%, respectively. Eleven pathogenic or likely pathogenic mutations were identified in 13 patients, among the mutation sites 7 were never reported before in Asian populations. The age at diagnosis of BRCA1/2 mutation carriers was older compared with non-mutation carriers (44.73 vs. 35.39 years; P=0.001) in this cohort. BRCA1/2 deleterious mutation carriers had a significantly lower chance of human epidermal growth factor receptor-2 (Her-2) positive status (P=0.010), higher tumor grade at diagnosis (P=0.009), higher probability to have a family history (P=0.016) and older age at diagnosis. Estrogen receptor (ER) and progesterone receptor (PR) status were significantly different between BRCA1, and BRCA2 mutation carriers (P=0.007). The current interpretation of BRCA1/2 status can only explain a small part of hereditary high-risk breast cancer. However, BRCA1/2 gene testing should still be recommended for women with a family history of breast cancer, as well as patients with breast cancer with specific pathologic types, which may be useful to make appropriate clinical decisions for treatment and prevention.