Background: Triple Negative Breast Cancer (TNBC) has a unique microenvironment of Tumor Infiltrating Lymphocytes (TILs). TNBC tumors are more likely to exhibit chromosomal instability and potential mutations than other subtypes.
Objectives: The study aims to evaluate the prevalence of CD8+ TILs biomarker by IHC in TNBC patients and its prognostic value. The greater number of TILs, the higher probability of response to chemotherapy. TILS suggest a likely option for immunotherapy in this disease.
Patients and Methods: CD8+ as a marker for TILs in the paraffin wax block of pre-treatment biopsies of 30 TNBC patients was evaluated, and its prognostic value by correlating it with OS and PFS was done. The study took place at the department of Clinical Oncology and Nuclear medicine Ain Shams university and Matarya teaching hospital.
Results: All patients (100%) were positive for CD8+, with a range of (1% to 60%), most of the patients (20 patients) had CD8 % between (10% to 20 %). High levels of CD8 + TILs were good prognostic indicators. Association of CD8+ TILs infiltrate status with longer PFS and OS in TNBC patients was recorded, but was not of statistical significance probably due to small sample size. Our study showed no correlation between CD8+ level and some clinical-pathological variables (tumor size, nodal status, tumor stage, menopausal status, age, family history).
Conclusion: All TNBC patients included in the study were positive for CD8+. High levels of CD8 + TILs are good prognostic indicators in TNBC. High CD8+ TILs infiltrate status was associated with longer PFS and OS in TNBC patients. Quantification of CD8 + TILs is feasible using routine immunohistochemical techniques.