Genetic Testing and Analysis in Breast Cancer Patients in Greece.

Introduction Genetic testing for inherited breast cancer predisposing pathogenic variants (PVs) inform treatment choices and guide clinical management strategies in breast cancer patients. Methods The study enrolled 146 patients, sourced from the Breast Unit database of the First Department of Obstetrics and Gynecology at the University of Athens, Alexandra Hospital. Blood samples were collected for genetic testing, utilizing a detailed 94-cancer gene panel. The results were then descriptively correlated with the clinicopathological data of the patients. Results In this study, 17 PVs were identified across several genes, BRCA1 (10), BRCA2 (3), CHEK2 (3) and TP53 (1), while 4 variants of unknown clinical significance (VUSs) were found in BRCA2 (1), CHEK2 (1), BRIP1 (1), MSH2 (1). This corresponds to a prevalence rate of 11.6% (17/146). Cascade testing was conducted for 7 of the 17 positive families, resulting in 11 individuals being tested, of whom 3 tested positive.  Conclusions Our study findings on the selected Greek population align with current literature. Genetic testing following National Comprehensive Cancer Network (NCCN) guidelines offers valuable insights for patients and their families. This information enhances counseling and identifying germline PVs could refine treatment strategies, potentially improving prognostic outcomes.