Clinical and morphological features of molecular-genetic clusters in triple negative breast cancer

Breast cancer is the most common malignant tumors in women in the world. One of most unfavorable biological breast subtype ― is the triple negative breast cancer (TNBC). It occurs in young age, and characterized high rate of locoregional rates and distant metastases. Currently, according to molecular genetic profiling, TNBC ― is a group of tumors with different prognosis, course and response to treatment. In our study we analyzed the molecular genetic profiling of 246 cases of triple negative breast cancer. 45 genes were included in our gene signature. Using K-means clustering method, it was possible to identify 4 tumor clusters with different clinical and morphological features. The most indicative were patients of clusters 2 and 3, since it was in these clusters that most of the proposed genes were overexpressed. Cluster 1 characterized by hypoexpression of most genes, while patients of 4 cluster characterized average values of most genes. Each of resulting clusters had «molecular genetic» portrait, which provided information about the predominance of certain signaling pathways in the tumor, the impact of which can be used as an additional option in the treatment of patients with TNBC. It was possible to identify clinical and morphological features that were statistically significantly different (p≤0,05) in the presented molecular genetic clusters: clinical stage, status of regional lymph nodes, histological subtype, degree of tumor differentiation, Ki67 level. In addition, when we comparing the immunohistochemical (IHC) subtype of the tumor with the molecular type of the tumor, it turned out that the most heterogeneous cluster was the cluster 4, in which only 64,1% of tumors were true triple negative. Thus, molecular genetic profiling of triple negative breast cancer, in our opinion, should be considered as a perspective diagnostic method for this disease, as it will help to choose a correct and personalized treatment for an individual patient.