Evaluation of BRCA1/2 gene mutations in patients with high-risk breast and/or ovarian cancer in Turkey

Abstract

Objectives: To find BRCA1/2 test selection criteria unique to the Turkish population, as well as to provide the BRCA1/ 2 gene mutation distributions of patient population to the literature. Methods: Genetic counseling was given to 2,373 cases with a family history of high-risk breast and/or ovarian cancer who applied to Istanbul University, Oncology Institute, Department of Cancer Genetics between 1994 and 2021 and selected by NCCN Guidelines for the BRCA1/2 test criteria. In our clinic, mutation screenings in BRCA1/2 genes were performed by Sanger sequencing method in patients admitted between 1994 and 2014 and by NGS method in patients admitted between 2015 and 2021. Results: The overall mutation rate in our patient group selected from high-risk patients was 16.5% (391/2,373) after BRCA1/2 gene mutation screening performed in 2,373 cases who applied to the Cancer Genetics clinic. Of the patients with mutations, 57.5% (225/391) had BRCA1 mutation, 41.9% (164/391) had BRCA2 mutation, and 0.6% (2/391) had both BRCA1 and BRCA2 pathogenic mutations. People diagnosed before the age of 60 who have a history of triple-negative breast cancer had a 28.5% overall mutation rate. Conclusions: BRCA1/2 mutation in Turkish population were evaluated in accordance with NCCN BRCA1/2 genetic test selection criteria; we discovered that all of our study results were statistically significant (p<0.05).