Pathological features of BRCA-mutated breast cancer in Shenzhen, China: a single-center study

Abstract Objective: To analyze and compare the pathological characteristics of BRCA-mutated and non-BRCA-mutated breast cancer patients at Shenzhen People's Hospital. Methods: A retrospective analysis of 409 breast cancer patients (2016–2024) meeting inclusion criteria was conducted using next-generation sequencing for genetic testing and SPSS for statistical analysis. Results: 1. In the BRCA group, 35 cases (68.6%) had tumor sizes ≤2 cm; 18 cases (35.3%) had positive axillary lymph nodes; 48 cases (94.1%) were invasive carcinoma; and 29 cases (56.9%) were histological grade III. 2. In molecular subtyping, the BRCA1 group had 20 cases (74.1%) of triple-negative type, whereas the BRCA2 group had 8 cases (36.4%) of Luminal A and 11 cases (50.0%) of Luminal B. Conclusions: This population-based study found that among breast cancer patients in Shenzhen, China, tumors with BRCA gene mutations were predominantly invasive carcinomas, frequently associated with axillary lymph node metastasis and grade III histological characteristics, compared to sporadic breast cancers. BRCA1-mutated breast cancers showed a statistically significant tendency toward the triple-negative molecular subtype. This statistically significant finding aligns with international research. International studies indicate that BRCA2-associated breast cancers often exhibit Luminal-type characteristics. However, because all study participants were of Chinese ethnicity, the results showed that BRCA2-associated breast cancers in the Chinese population in Shenzhen showed no significant predisposition to Luminal-type molecular features compared to sporadic breast cancer patients.