The role of androgen receptor expression and T-lymphocytes infiltration in the tumor stroma in patients with triple-negative breast cancer.

Simple Summary: Breast cancer is the most common invasive cancer among women. Triple-negative breast cancer (TNBC) accounts for 15–20% of newly diagnosed breast cancers and has the worst prognosis. However, TNBC patients are not a homogeneous group, and there are differences in the course of the disease as well as in response to treatment. For this reason, differentiation of subtypes of this tumor is important for optimal therapeutic decision and risk prediction. The presented study focuses on the expression of the androgen receptor (AR) and the infiltration of T-lymphocytes in the tumor stroma (TILs) of TNBC patients. Correlation of these tested biomarkers with standard prognostic factors. Defining new prognostic factors for 3-year overall survival (OS). Abstract: Background: Analysis of the practical benefit of testing the expression of AR and the TILs in patients with TNBC and their correlation with standard prognostic factors. Methods: The study group consisted of 86 female patients treated for TNBC. T-lymphocyte infiltration was examined in H+E staining. AR expression, CD8 and CD4 T-lymphocytes were evaluated in immunohistochemistry. Results: Significantly negative correlation was found between AR expression and the CD8 T-lymphocyte infiltration levels. A significant negative correlation was found between the AR expression and G and Ki 67, and a positive correlation between the TILs levels and G and Ki 67. Patients with AR expression and low TILs levels had the highest percentage of diagnosed distant metastases and 3-years OS. Patients with high TILs no distant metastases or deaths were diagnosed. The level of TILs turned out to be a significant independent prognostic factor. Conclusions: Based on the assessment of AR expression and TILs infiltration, the group of highest and lowest risk was determined. The prognostic factor of known parameters such as TNM and a new factor - TILs was confirmed. On the other hand, parameters such as G and Ki 67 and the tested factor - AR had no effect on the prognosis.