Morphological and Prognostic Characteristics of Breast Cancer in Women Living in the Sakha Republic (Yakutia)

Background: This article presents the results of the analysis of the clinical and morphological examination of breast cancer (BC) in women of the Republic of Sakha (Yakutia) (RS(Y)). Methods and Results: The object of the study was fragments of breast tissue from 294 women who underwent surgical treatment and/or needle biopsy. By ethnicity, there were 118(40.1%) women of indigenous nationalities and 176(59.9%) women of non–indigenous nationalities. The greatest number of cases of BC was registered in the age group of 50-59 (32.6%). The age group of 40-49 was in second place (20.4%). Among the indigenous population, women in the age groups of 40-49 years (23.7%) and 50-59 years (26.3%) predominated. The age groups of 50-59 years (36.9%) and 60-69 years (22.2%) predominated among the non-indigenous women. Tumors with a size of 2 cm to 5 cm prevailed; they were detected in 185(62.9%) women. Tumors with a spread to the chest wall and skin develop more often in women of non-indigenous nationalities (15.9% of cases), than in women of indigenous nationality (6.8% of cases). Regardless of ethnicity, the most common histological form of BC in women of the RS(Y) was infiltrative ductal cancer (65.3%). Cancer staging according to the TNM staging system showed that n the age group of women under 39 years, Stage IIIB+IIIC (43.2%) was most often registered (p=0.01), while in other age groups, Stage IIA (32.4%) was more often noted. Conclusion: Our findings suggest that further investigation of the peculiarities of the course of BC in the female population of Yakutia would lead to much improved methods of diagnosis and treatment.