Abstract: Objective The frequency of BRCA1 / 2 gene mutations varies greatly in different regions and ethnic groups. This study aimed to analyze the BRCA1 / 2 gene mutations in breast cancer patients in western Hainan and their impacts on the prognosis. Methods A total of 256 patients who were diagnosed with primary breast cancer and hospitalized in Hainan Western Central Hospital from October 2015 to December 2020 were regarded as the research objects. Denaturing high-performance liquid chromatography ( DHPLC) was applied to screen the BRCA1 / 2 gene mutations in breast cancer patients. The BRCA1 / 2 gene mutation status and clinical characteristics of the 256 patients were analyzed, the 5-year survival rate of the patients with BRCA1 / 2 gene mutations was analyzed, and the factors that affect the prognosis of the patients were analyzed by COX regression. Results Among the 256 breast cancer patients in this study, 53 patients had BRCA1 / 2 gene mutations, in which the BRCA1 mutation rate was 12. 11 % (31 / 256), the BRCA2 mutation rate was 8. 59 % (22 / 256), and the rate of harmful variants was 7. 03 % (18 / 256). There were significant differences in family medical history, gynecological disease history, breast disease history, positive ratios of estrogen receptor (ER) and CerbB-2 proteins, clinicopathological grade and clinical stage between patients with BRCA1 / 2 mutations and those without BRCA1 / 2 mutations (P < 0. 05). The overall survival rate of the 256 patients was 83. 59 % , and the survival rate of patients with BRCA1 / 2 gene mutations was lower than that of patients without mutations (P< 0. 05). COX regression analysis showed that BRCA1 / 2 mutations, breast disease history, clinical stage, CerbB-2 positive, CEA and CA199 were all risk factors affecting the survival of breast cancer patients ( P < 0. 05). Conclusion DHPLC can effectively screen out the harmful variants of BRCA1 / 2 gene in breast cancer patients, and the BRCA1 / 2 gene mutations are closely related to the clinicopathological features and prognosis of breast cancer patients. 

Key words: breast cancer, BRCA1 / 2 gene, gene mutation, prognosis