A Study on Tumor-Infiltrating Lymphocytes in Different Subtypes of Breast Cancer

Summary The study aimed to investigate immune cell infiltration in different subtypes of breast cancer (BC). Retrospectively were selected 100 patients with primary BC, grouped into four molecular surrogate (Luminal A and Luminal B-like, HER2-positive triple-negative - TN), determined by immunohistochemistry (IHC). In each patient, a percentage stromal tumor-infiltrating lymphocytes (TILs) was hematoxylin-eosin staining. IHC performed using antibodies CD3, CD4, CD8, CD20, FOXP3. Immunophenotyped counted (separately intratumoral stromal) semi-quantitatively graded. the studied tumors, 10% defined as lymphocyte-predominant BC. high count TILs subsets found mainly TN stroma is preferred localization for cells all BC subtypes. CD3+ T predominates over CD20+ B lymphocytes, CD8+ cytotoxic FoxP3+ regulatory dominating HER2 are more immunogenic than – like T-cells’ response predominant cases predominance Tc Foxp3+ Treg located stroma.