Primary operable breast cancer: molecular subtypes and morphological prognostic factors

Abstract

Aim. To study the immediate and long - term results of treatment of patients with a primary operable breast cancer, depending on the morphological and biological characteristics of the tumor. Materials and methods. The retrospective study included 974 patients aged from 30 to 82 years (a mean age of54.5 years) with a primary operable breast cancer (T1-2N0-1M0) observed from 2005 to 2012. The overall survival (OS) and disease - free survival (DFS) were studied depending on the histological type, molecular - biological subtype of breast cancer, axillary status, lymphovascular invasion, tumor histologic grade, proliferation index (by Ki-67 staining) and HER2 protein expression. Statistical data processing included a comparison of the frequencies of the studied traits, analysis of survival curves by the Kaplan-Meier method.Results. Indicators of a 5-year OS and 5 and 10-year OS and DFS were lower in carcinomas of mixed type compared with invasive carcinoma of no special type ( p =0.03) and invasive lobular carcinoma ( p =0.01). In the absence of metastases in regional lymph nodes, indicators of 5 and 10-year OS were higher compared with the macrometastatic involvement of one ( p =0.02) or two or more lymph nodes ( p =0.004): 96.0% and 89.3%; 95.4% and 79.0%; 88.9% and 79.3%, respectively. A similar trend has been noted for indicators of 5 and 10-year DFS. The OS in the absence of metastases in the lymph nodes was greater with the luminal B HER2-positive subtype and triple - negative breast cancer. The degree of malignancy of the tumor had no effect on OS. The probability of disease recurrence was significantly higher in patients with a degree of G3 compared with G1 ( p =0.00001) and G2 ( p =0.002): the rates of 5 and 10-year - old DFS were: 84.8 and 55.0%; 94.1 and 86.0%; 88.9 and 72.2%, respectively. The expression of HER2 and Ki-67 proliferation index influenced the DFS without affecting the OS.Conclusions. The morphological factors deteriorating the OS and DFS of patients with primary operable breast cancer are the presence of macrometastases in regional lymph nodes, the defeat of two or more lymph nodes, the presence of lymphovascular invasion, mixed histological form of breast cancer. The subtypes with a more aggressive course include: HER2-positive tumors, triple negative breast cancer.