Predictive relapse model in patients with luminal HER2-negative breast cancer

Luminal HER2-negative breast cancer (BC) detected at early stages is characterized by a relatively favorable course. However, in some cases, there may be a relapse of the disease regardless of the treatment. The aim of the study was to identify predictors of recurrence of primary resectable luminal HER2-negative breast cancer. Materials and Methods. The authors examined biopsies of patients' breast tumors (n=158) with luminal HER2-negative breast cancer, stage T1-2N0-1M0, as well as anamnestic data of patients. All women were divided into 2 groups: with disease recurrence within the next 5 years after surgery (n=53) and relapse-free patients (n=105). Macroscopic tumor characteristics, its malignancy, total malignancy score, Nottingham prognostic index, Ki-67, expression of receptors for estrogen and progesterone and their influence on relapse were studied. The authors analyzed expression levels of miRNA (miRNA-21, miRNA-221, miRNA-222, miRNA-155, miRNA-205, miRNA-20a, miRNA-125b, miRNA-146b, miRNA-200a) in tumor tissues. Statistical data processing was performed using Statistica 7 (StatSoft Inc., USA) and MedCalc (version 15.2) software. Results. Comparative analysis of miRNA expression levels between groups of patients with recurrent breast cancer (n=21) and relapse-free patients (n=20) revealed a statistically significant increase in the expression levels of miRNA-21, miRNA-205, miRNA-146b, and miRNA-200a in the group with recurrent disease. The authors established the predictive role of the ratios of the expression levels of potentially oncogenic and tumor suppressive miRNA-21/miRNA-155 and miRNA-21/miRNA-205, as well as the role of miRNA-20a in breast cancer recurrence in combination with Ki-67, disease stage, and primary tumor size. Based on the data obtained, they developed a prognostic model to determine the recurrence of primary operable luminal HER2-negative breast cancer. Conclusion. The created prognostic model allows to clearly stratify the prognosis of primary operable luminal HER2-negative breast cancer.