Expression of FOXP3 of Tumor-Infiltrating Lymphocytes in Invasive Breast Cancer: Its Relationship to Histopathological Parameters and Overall Survival

Abstract

BACKGROUND: Forkhead box P3 protein (FOXP3) is expressed in both tumor cells and tumor-infiltrating lymphocytes (TILs) and is reported to be associated with differences in clinical outcomes. Recent literature shows that FOXP3 positive (FOXP3+) T regulator cells (Tregs) influence anti-tumor immunity in solid tumors.
 АIM: To explore FOXP3+ Tregs expression related to various prognostic factors in breast carcinoma (BC) in the central Indian population. Our study is also helpful in correlating the role of FOXP3+ Tregs in the survival of invasive ductal BC with different histopathological presentations.
 MATERIALS AND METHODS: This is a retrospective and prospective observational study in which FOXP3+ Tregs was counted in the peritumoral area by immunohistochemistry in 47 consecutive cases of BC operated on and diagnosed already. The patients were followed for 48 to 69 months for disease progression.
 RESULTS: High-grade tumors are prevalent (n = 30) in the study area irrespective of the stage of clinical presentation. Patients who could adhere to their treatment plan remained free of adverse outcomes until the end of our follow-up period of 69 months (p = 0.001). No molecular subtype in our study showed specific predilection towards a high Tregs count in the peri-tumoral area. No other clinical or pathological parameters significantly correlated with FOXP3 +Treg count, including overall survival and disease-free survival.
 CONCLUSION: The study shows that luminal human epidermal growth factor receptor 2 negativ and human epidermal growth factor receptor 2 enriched BC show comparatively high FOXP3+ Tregs count. There is no relation with tumor grade, TNM stage, important immune markers, or overall survival and disease-free survival.