Publication:

Correlation of tumor infiltrating lymphocytes in invasive breast carcinomas: a morphological study

Background The aim of the study is to analyse the stromal tumor-infiltrating lymphocytes (sTILs) in invasive breast carcinomas and assess the percentage of sTILs in invasive breast carcinomas using a single H and E slide following a standardized protocol. Also, to study the correlation between sTILs and known prognostic factors.

Methods Two year retrospective study of 190 cases using a single representative H and E slide examined by 2 observers. TILs assessed based on current recommendations from the 2014 International TILs Working Group (ITWG) for the evaluation of TILs. Histological type, histological grade, molecular subtypes using relevant IHC markers, number of lymph nodes isolated, number of lymph nodes positive with extracapsular invasion, lymphovascular invasion, perineural invasion, TNM stage and tils in percentage were documented.

Results The collected data was analysed with IBM SPSS statistics for Windows, version 23.0. Correlation of TILS with age, SBR grade, ER, PR, Ki67, molecular subtype-showed statistical significance with an acceptable p value.

Conclusions Many studies have supported the evidence of TILS, in different levels and density which is predictive of response to neoadjuvant chemotherapy. In certain breast carcinoma subtypes, it has a prognostic value in patients treated with adjuvant chemotherapy. From our study TILs show a correlation with few of the known prognostic factors. There is a paucity of data in Indian literature on TILs and its implications. Understanding of the role of TILs regarding could be of importance in devising novel immunotherapeutic strategies in breast cancer treatment.