Prognostic significance of evaluation of tumor infiltrating lymphocytes in triple-negative breast cancer in residual disease postneoadjuvant chemotherapy

Abstract

Background: Triple-negative breast cancer (TNBC) are highly heterogeneous tumors and are not eligible for
hormonal therapies or human epidermal growth factor receptor type 2(HER 2)-targeted agents and they are
associated with failure to achieve pathological complete response (pCR) and has unfavorable prognosis. In the
residual disease (postneoadjuvant chemotherapy and surgery) of cases of TNBC, identification of parameters
for risk stratification is needed for better identification of high-risk patients who require additional systemic
treatments. Tumor-infiltrating lymphocytes (TIL’s) are a part of the tumor microenvironment and they are
indicator for monitoring immune response and they influence cancer growth, progression, and metastasis.
With the success of immunotherapy in various cancers, there is an increasing interest in directly targeting
the immune system in TNBC.
Material and Methods: In our study, 115 TNBC cases were taken and stromal TIL’s were calculated on H and
E stained slides and TIL grades (scoring according to International TIL’s Working Group) were compared
with clinicopathological parameters and overall survival.
Results: Statistically significant correlation was found between Stage of presentation, axillary lymph node
positivity, relapse, metastasis, and TIL (P < 0.0001). High stage of the tumor, axillary lymph node positivity,
cases of relapse, metastasis was associated with Low-grade TIL. High-grade TIL showed a good overall
survival (100%) in comparison to intermediate grade TIL 2 (90%) and low-grade TIL 1 (52%).
Conclusion:TIL scoring in residual disease post neoadjuvant chemotherapy can help in the stratification of
high-risk cases and can help in prognostication.