Breast cancer associated with CHEK2 mutation carriage

The paper presents clinical cases in which the patients were diagnosed with breast cancer (BC) associated with mutations in the CHEK2 gene. Objective. To investigate the characteristics of treatment and prevention in patients with BC associated with CHEK2 mutation carriage. Subjects and methods. In 2016-2017, the P.A. Herzen Moscow Oncology Research Institute treated three patients diagnosed with BC associated with CHEK2 mutation carriage. Two cases underwent preventive surgery: prophylactic subcutaneous mastectomy with single-stage reconstruction in one case and prophylactic bilateral tubo-ovariectomy in the other. A further follow-up of these patients and their relatives will be able to draw conclusions about the correctness of preventive surgery policy. Results. In all the three clinical cases, the patients were diagnosed with germline missense I157T mutation (p.I1e157Thr) in exon 3 of the CHEK 2 gene, which results in amino acid substitution (isoleucine to threonine at codon 470 – c.470T>C) in a heterozygous state. The volume of surgical interventions for BC, preventive surgery on the breast and ovaries in our patients was decided individually based on their clinical data. Genetic examination of their relatives is needed for primary prevention of BC. Conclusion. There is a need for further investigations in patients with BRCA1, 2, CHEK 2 mutations, as there will be a growing number of patients with mutations in these genes due to a larger number of genetic laboratories. Knowing the characteristics of inheritance and development of hereditary BC, it is necessary to elaborate surgical treatment policy for these patients, algorithms for follow-up of the patients, and an algorithm for examination and prevention of BC among their relatives. © Bionika Media Ltd.