OBJECTIVE
To determine the clinical and morphological characteristics of BRCA-associated breast tumors.
MATERIAL AND METHODS
Blood samples were collected from 722 patients with breast cancer (BC). Mutations were analyzed using pyrosequencing on a PyroMark Q24 (Qiagen, Germany). A Piroscreen BRCA-screen kit (Amplisens, Russia) was used to determine the 6 most common mutations in the Slavic population. The findings were compared with clinical and morphological characteristics. Sixty-two (8.6%) of the 722 samples had a mutation in BRCA1.2 genes. The common mutations were 5382insC (75.78%), 300T>G (11.33%), and 2080delA (6.45%). The patients’ mean age was 43.2 years. A family history of cancer was present in 88.88% of patients. 100% of cases were correctly diagnosed with high-grade (G3) invasive carcinoma of no special type being seen in 65.31% of cases. There was no immunohistochemical staining for most BRCA-deficient tumors. A triple negative cancer phenotype was observed in 64% of the patients with mutations. There was a high level of the proliferation marker Ki-67 in 52 (88.13%) cases.
RESULTS
BRCA-associated BC occurred in 8.6% of patients in the Sverdlovsk Region. The clinical features in patients with mutations were early-onset disease manifestation, a primary multiple process, and a compromised family history. The isolated findings of X-ray mammography and breast ultrasound and MRI indicated benign breast changes in the absence of specific features. Only complex diagnosis made it possible to reliably evaluate the image. Morphologically, these were G3 invasive carcinomas of no special type with high proliferative activity. In most cases, the tumors were of the basal subtype, not expressing any of the three receptors.
CONCLUSION
Examination of women to detect mutations in BRCA1.2 genes is an integral part of the diagnostic algorithm for identifying the hereditary forms of BC. Genetic testing should be done in patients with a moderate or high risk for BC, as well as in those with an immunohistochemical subtype of triple-negative cancer.
