Higher prevalence of BRCA2 mutations among Chinese breast cancer patients in a community oncology clinic.
e12017 Background: According to a large US population-based study, BRCA1 and 2 mutations occur in about 6 and 4% breast cancer cases age <45. Asians have the lowest prevalence of BRCA1 mutation among five US racial groups. The prevalence of BRCA1 and BRCA2 mutations was reported as 8.1% and 2.7% among pts with family history in Shanghai, compared to 4.9% and 7.5% respectively in Hong Kong. We would like to explore the BRCA mutations in a clinic located in an Asian-majority community in California. Methods: Consecutive female breast cancer pts selected for BRCA testing according to NCCN guidelines are retrospectively studied from 10/2009 to 10/2011. Sequencing of all translated exons and immediately adjacent intronic regions of the BRCA1 and BRCA2 was performed on the peripheral blood (Myriad, Utah). Results: Twenty-six pts were included in this study. Six pts have bilateral breast cancers; 2 synchronous and 4 metachronous with intervals of 11-13 years. Nine pts (34.6%) had BRCA2 germline mutations, of which 5 were considered deleterious and 4 of uncertain significance. Eleven pts (42.3%) had no BRCA mutation. BRCA results were unavailable in six pts because they were either not yet done or denied by health insurance. Conclusions: 1. High prevalence of BRCA2 mutation is seen in our pts selected according to NCCN guidelines. The presence of BRCA2 but not BRCA1 mutation in our study is intriguing. 2. Triple negative breast cancer is not more prevalent in BRCA2 mutation carriers. 3. Similar frequency of family history of breast/ovarian cancer is noted among pts with or without BRCA2 mutation, deleterious or of uncertain significance. The role of the BRCA2 mutation of uncertain significance needs to be further elucidated. 4. Due to the small sample size, further study is required to confirm our findings. [Table: see text]