Anna-Mária Tőkés1, Csilla Szundi1, Orsolya Rusz1, Janina Kulka1
1. Semmelweis University Budapest, 2nd Department of Pathology
Introduction: Tumor infiltrating lymphocytes (TIL) are considered to play an essential role in mediating response to chemotherapy and improving clinical outcomes in breast carcinomas (BC).
Aims: I. To assess stromal TIL (StrTIL) on HE stained slides of surgically resected BC tissues and to correlate TIL ratios with subtype and patients’ follow-up data (cohort I).
II. To analyse the prognostic value of StrTIL changes in a cohort of breast carcinoma cases treated with neoadjuvant chemotherapy (cohort II).
Patients and methods: StrTIL was evaluated based on the recommendations of the International TILs working group (2014). Totally 220 hormone receptor positive (HR-positive) and 101 HR-negative BC cases were analysed in cohort I. In the neoadjuvant cohort (cohort II) 65 HR-positive and 47 HR-negative cases with both pre and postoperative tumor sample available were included. ∆StrTIL was defined as the difference between post-operative StrTIL in surgical specimen and pre-operative StrTIL in core biopsy. Distant metastasis free survival (DMFS) was recorded.
Results: In the cohort I. significantly higher StrTIL ratio was observed in HR-negative BC subgroups compared to HR-positive groups (p<0.001), and high StrTIL ratio was also significantly inversely associated with DM formation (p=0.011). 22.2% of the cases with no distant metastasis presented high (≥10%) StrTIL content. In metastatic group this ratio was 12.5%.
In cohort II. both post-StrTIL and ∆StrTIL had independent prognostic role in HR negative cases. Each 1% increase in post-StrTIL reduced the hazard by 2.6% of distant metastases development and for each 1% ∆StrTIL increment, the risk of distant metastases was reduced by 4.3%. The prognostic role of StrTIL in HR positive cases could not be proven.
Discussion: StrTIL is a promising prognostic marker in at least HR-negative BC. HR-negative BC with intermediate or low levels of pre-treatment StrTIL may benefit from an intervention (ex. treatment with specific cytotoxic chemotherapyy) that may increase TIL.
New National Excellence Program (ÚNKP-17-4-III-SE-71)
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