Association Of Tumor Infiltrating Lymphocytes With Histopathological Parameters In Breast Cancer

Abstract

Breast cancer remains a leading cause of cancer-related mortality among women worldwide. Tumor-infiltrating lymphocytes (TILs) have emerged as potential immunological markers for assessing prognosis and clinical outcomes in breast cancer. This study aims to evaluate the association between TILs and histopathological prognostic factors in primary breast cancer, following the International TILs Working Group's guidelines. A retrospective analysis was conducted on 100 breast cancer specimens collected at Sri Devaraj Urs Medical College between January 2018 and September 2023. Histopathological parameters, including tumor grade, necrosis, lymphatic invasion, vascular invasion, perineural invasion, axillary lymph node metastasis, Nottingham prognostic index (NPI), and stromal changes, were assessed alongside TILs quantification.

The results revealed a significant correlation between TILs and key prognostic factors such as tumor grade (p=0.03), necrosis (p<0.0001), NPI (p=0.04), and N stage (p<0.0001). High TIL infiltration was associated with Grade 1 tumors, lower NPI categories, and decreased nodal metastasis. Additionally, TIL levels were inversely related to tumor necrosis and advanced N stages, indicating reduced immune response in more aggressive cancers. The findings suggest that TILs can serve as a cost-effective prognostic marker in resource-limited settings and hold potential for guiding immunotherapy strategies. Limitations include the lack of molecular subtype classification and neoadjuvant/adjuvant setting analysis, warranting further research to standardize TIL evaluation in breast cancer diagnostics.