HEREDITARY CANCER MUTATIONS PREVALENCE AMONG BREAST CANCER PATIENTS ACCORDING TO NGS PANEL TESTING RESULTS, ITS IMPORTANCE IN CHOOSING THE EXTENT OF SURGICAL TREATMENT

Abstract

Summary. Genetic testing for hereditary cancer gene mutations is important for breast cancer patients in many aspects (including the degree of risk determining the extent of surgical treatment) and helps the patient to choose the best option, both from the point of view of risk reducing, and from the point of view of the best aesthetic result and minimizing the consequences of treatment. Aim: to determine the spectrum of gene mutations in breast cancer patients who had at least one of the risk factors for heredity of the disease. Object and methods: the study included 160 breast cancer patients who had at least one of the risk factors for heredity of the disease according to the criteria defined in the NCCN version 2.2019 guideline. All patients underwent next-generation DNA sequencing (NGS) genetic testing for a panel of 30 hereditary cancer genes. Statistical analysis of the obtained results was carried out in the EXCEL. Results: among 160 patients, 90 mutations were detected in 72 patients (45.0%). Among them, 59 patients (81.9%) had one mutation, 13 patients (18.1%) had more than one mutation. 51 pathogenic or likely pathogenic mutations were detected in 45 patients. 39 VUS (variant of uncertain significance) mutations were detected in 31 patients. The rate of hereditary breast cancer among the studied patients was 27.5%. The most frequent gene mutations were: BRCA1 (47.1%), CHEK2 (17.6%), BRCA2 (17.6%), ATM (5.9%), PALB2 (3.9%), BRIP1 (2, 0%), others (5.9%). Among them, the most frequent mutation was 5382ins C of the BRCA1 gene. For 64.3% of patients, the results of genetic testing had the highest importance when choosing the extent of surgical intervention, and for only 5.1% of patients they were completely unimportant. Conclusion: genetic testing is important for patients in many aspects, from the choice of the scope of surgical treatment to the features of followup, preventive measures to reduce the risk of new events (multiple primary neoplasms), the feasibility of testing children, etc. It is relevant to continue studying the role of genetic testing for breast cancer patients in various aspects, in particular, in choosing the scope of surgical treatment.