Abstract

Triple negative breast cancer (TNBC) is an aggressive subtype characterized by the absence of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expressions. Tumor-infiltrating lymphocytes (TILs) play a crucial role in the immune response against TNBC, potentially influencing disease progression and treatment outcomes. This study investigated whether the presence and distribution of TILs in TNBC are affected by BRCA gene alterations, given the potential implications for immunotherapy and treatment strategies. We conducted a retrospective analysis of TNBC cases, categorizing them into two groups: those with BRCA gene alterations and those without. We assessed the quantity and spatial distribution of TILs within tumor samples using immunohistochemistry and analyzed the clinical characteristics of the patient cohorts. The results of this study reveal that the amount and organization of TILs in TNBC remain largely unaffected by BRCA gene alterations. There was no significant difference in TIL density or distribution between the two groups. These findings suggest that the immune microenvironment in TNBC is primarily driven by tumor-specific factors and characteristics of the tumor microenvironment, rather than BRCA gene status. This study contributes to our understanding of the immune response in TNBC and underscores the need to explore alternative strategies to enhance immunotherapy efficacy in this aggressive breast cancer subtype. Further research is required to identify factors influencing TIL recruitment and activation in TNBC, ultimately leading to improved treatment approaches for this challenging disease.