[Breast cancer with triple-negative phenotype in the Russian patient population. Clinical and morphologic features]

The purpose of this study was to examine the incidence of breast cancer with triple-negative phenotype (TN BC) in the Russian population as well as to compare the clinical and morphological features and outcomes for women with TN BC with other types of breast cancer. We studied a cohort of 499 patients with breast cancer without distant metastases, diagnosed between 2002 and 2011 at N.N.Blokhin Russian Cancer Research Center in Moscow. Triple-negative breast cancers were defined as those that had "negative" level of estrogens and progesteron receptors and were HER2neu negative. 330 (66.2%) of patients has triple negative tumors, 81 (16.2%)--ER and PR negative and HER-2 positive tumors, and 88 (17.6%)--ER and/or ER positive and HER-2 negative tumors. Further was evaluated disease-free and overall survival. 18.5 % of all analyzed patients had triple negative phenotype. Median follow-up was 40.5 months. Characteristic features of the TN BC were: TN breast cancer, compared with other subtypes, characterized by a higher incidence of clinical and morphological features associated with an aggressive course of the disease: the age less than 35 years, grade 3, non- specified invasive histology, high level of Ki-67, the rapid development of the disease, which manifests itself in small terms of the first complaints before the diagnosis. TN BC patients has poorer 5-year overall survival (73.6 + 3.6%) and the 5-year disease-free survival (70.6 + 3.5%), which is significantly lower than the comparable survival of patients with other subtypes of breast cancer (p < 0.001). The results of our study confirm the similarity of majority of clinical and morphological characteristics, course and prognosis of the disease of the Russian population of TN BC patients with those in Europe and the United States.