CD3+ Tumor-Infiltrating Lymphocytes in Breast Carcinoma: Their Prognostic Role and Association With Clinical Parameters.

Background Breast carcinoma cases are rising steadily and represent a major cause of mortality and morbidity in India. In response to breast carcinoma, the immune system is activated, resulting in lymphocyte infiltration in and around the tumor nests. This interaction between the tumor and immune system is the basis for studying tumor-infiltrating lymphocytes (TILs). Despite studies on TILs in breast carcinoma, the role of CD3+TILs in predicting patient outcomes remains underexplored. This study aimed to evaluate TILs in breast carcinoma tissues by analyzing CD3 expression through immunohistochemistry (IHC) and examining its association with various prognostic factors, such as histological grade, clinical stage, lymph node status, and hormone receptor status. Methods A study was conducted on 45 breast carcinoma cases, documenting various clinicopathological parameters. IHC staining was performed for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor (HER2-neu), and CD3 markers on tissue samples. Both intra-tumoral and stromal CD3 TILs were quantified and analyzed in relation to clinicopathological prognostic factors. Results In all 45 breast carcinoma cases, intra-tumoral and stromal CD3 expression was assessed. High stromal CD3 expression is documented in the triple-negative breast tumor. CD3 intra-tumoral expression correlated significantly with tumor size (p < 0.035), ER status (p < 0.036), and PR status (p < 0.036). CD3 stromal expression showed no correlation with any of the prognostic parameters.  Conclusion The current study found a strong correlation between CD3 intra-tumoral expression with tumor size, ER and PR status. The findings imply that CD3 may be a significant factor in breast carcinoma prognosis. There were more stromal CD3 TILs in triple-negative breast carcinoma (TNBC) cases. TILs ought to be examined for their capacity as novel prognostic and predictive indicators, especially in cases of invasive breast cancer, such as triple-negative breast carcinoma.