Assessment of Tumor Infiltrating Lymphocytes in Breast Cancer Patients and its Correlation with Clinico- Histopathological Characteristics and Molecular Subtypes

Background: Scoring of tumor infiltrating lymphocytes (TIL’s) in breast carcinoma specimens has gained increasing value as it has prognostic and predictive value in certain molecular subtypes of breast cancer especially triple negative breast cancer. The present study evaluated tumor infiltrating lymphocyte in breast carcinoma cases and correlated the response with age of the patient, tumor size, tumor grade, histopathological subtypes and molecular classification. Material and Methods: A cross-sectional observational study was conducted on 104 cases of invasive breast carcinoma from January 2024 to march 2025. Clinicopathological details like age of the patient, tumor size, histopathological type of tumor with grade and molecular classification were taken into account. Assessment of TIL was done based on International TIL working group recommendations and correlations were evaluated. Results: A total of 104 cases were studied. Majority of patients belonged to age group of 41 years to 50 years. Higher TIL response was found in young patients (<40years). 53.8%were having tumor size of 3cm to 5 cm. Cases with tumor size <3 cm have revealed highest TIL response. Maximum number of patients (66%) were having grade 3 tumor with marked TIL response (55%). Invasive duct carcinoma was the frequent diagnosis. Higher TIL was found in metaplastic carcinoma cases (75%). Majority of cases (39.4%) were luminal A subtype. Triple negative cases (basal type) showed highest TIL score (68.7%). Conclusion: This study validates the histomorphological evaluation of tumor-infiltrating lymphocytes as proposed by the International TILs Working Group in the Indian population and highlights its role as a cost-effective prognostic immune biomarker.