Mutation frequency in patients with hereditary breast cancer and its relationship with clinical/pathological parameters

Aim: The aim of this study was to investigate the frequency of hereditary and non-hereditary breast cancer in patients who were diagnosed with breast cancer. The study aims to determine the frequency of mutations in patients diagnosed with hereditary breast cancer, to evaluate local recurrence and survival rates in these patients and also to compare the findings with other data obtained in our hospital. We will also investigate whether hereditary breast cancer patients exhibit more aggressive tumour profiles due to genetic factors. This study aims to draw attention to the importance of genetic factors in breast cancer management and to contribute to clinical practice by comparing the data obtained with the literature. Materials and Methods: The study was planned retrospectively in Samsun University Faculty of Medicine, Department of General Surgery. Between 01.01.2015 and 31.12.2023, the data of a total of 538 patients who were diagnosed with breast cancer, operated and followed up were analysed. Demographic information, anamnesis and examination findings of the patients were obtained from the hospital database, E-pulse system and interviews with the patients. Nonparametric Mann-Whitney U test was used for differences between two independent groups, frequency distributions and Chi-square test (Fisher's exact test) were used for categorical data. Survival analyses were performed using the Kaplan-Meier method. Results: The mean age at diagnosis in patients with hereditary breast cancer was 39.8 years, indicating an earlier age at diagnosis compared to the non-hereditary group. Multifocality rate was 15,4% and triple negative subtype frequency was 25,6% in hereditary patients. In addition, the use of neoadjuvant treatment was 35,9% in hereditary breast cancer patients and 17,0% in non-hereditary patients. The recurrence rate was found to be 5,12% in hereditary breast cancer patients and 17,8% in non-hereditary patients. Conclusion: Our study shows that hereditary breast cancer patients are usually diagnosed at an earlier age and exhibit more aggressive tumour profiles. As a result of genetic analysis, BRCA1 was the most common mutation, and other mutations such as BRCA2, PRSS1, ATM, CHEK2 were also detected at a significant rate. In addition, higher rates of multifocality, triple negative subtype ( p=0,019 ) and neoadjuvant treatment ( p=0,006 ) use were found in the hereditary group. These findings suggest that hereditary breast cancer patients require more aggressive approaches in treatment planning. However, some findings, such as the low recurrence rate in the hereditary group, are inconsistent with the literature and should be investigated by comprehensive studies in future. Keywords: Breast cancer, Hereditary breast cancer, BRCA, Genetic analysis, Survival analysis