MEME KANSERİ HASTALARINDA BRCA MUTASYONLARININ KLİNİK VE PATOLOJİK ÖZELLİKLERE ETKİSİ

Abstract

This study was carried out retrospectively in breast cancer patients who were followed in Hacettepe University Medical Oncology Clinic and underwent BRCA gene analysis in line with the recommendations of the National Comprehensive Cancer Network (NCCN). We aimed to determine the differences between the clinical and pathological characteristics, treatment method, response rates, and survival of mutation carriers and those who do not. We evaluated 636 patients who had undergone BRCA gene analysis. Pathogenic mutations were detected in a total of 139 (21.9%) patients, including 65 BRCA1, 71 BRCA2, and three BRCA1+2. A triple-negative breast cancer diagnosis at ≤60 years, strong breast or ovarian cancer history in close relatives, and having more than one NCCN criteria were higher in those with pathogenic BRCA mutations (p<0.001). Infiltrative ductal carcinoma (IDC) was the most common in all groups, but tumors with medullary and metaplastic characteristics were more common in BRCA1 carriers (p<0.001). In BRCA1 carriers, triple negativity, Ki67 proliferation index, and tumor histological grade were higher, whereas in BRCA2 carriers lymph node involvement and metastatic disease were more common at the time of diagnosis. We found more frequent brain metastases in BRCA1 carriers and liver metastases in BRCA2 carriers. The median follow-up period for the entire population was 5.8 years. The overall survival of patients with pathogenic BRCA mutation was shorter than the others (p=0.003). There was no difference in overall survival between BRCA results in triple-negative, local stage, and metastatic disease. In BRCA carriers, prophylactic breast surgery provided a disease-free survival advantage (p=0.032). In our country, large-scale studies are required to identify the groups to be analyzed for BRCA mutations in patients with breast cancer and to evaluate the BRCA2 mutation in terms of its founder effect. The follow-up and treatment of BRCA carriers diagnosed with locally advanced-stage breast cancer should be specified. BRCA carriers should be offered the option of prophylactic surgery more frequently.