Abstract 187P
Background
The immune system plays a central role in the pathogenesis of cancer, inhibiting as well as promoting effects on tumor development. Tumor-infiltrating lymphocytes (TIL) and PD-L1 expression have been described as factors with prognostic influence in the early stages of breast cancer. However, its relationship to other classical prognostic factors of estimated importance is unknown.
Methods
The primary endpoint was to analyse the relationship between the immune profile, characterized by TILs, CD3 and CD8 T lymphocytes and PD-L1, and the histological phenotype and other classical prognostic factors (histological grade, ki67, hormone receptors, HER2 neu). In this way, we analyzed 138 samples from patients with resected early breast cancer at our institution. TILs, CD3 and CD8 T lymphocytes were quantified in the tumor stroma. PD-L1 expression was measured in immune cellularity (IC) and tumor cells (TC) (PD-L1+ if ≥1% and PD-L1- if <1%).
Results
The median of the variables analyzed was: TILs 2% (interquartile range (IQR) 4); CD3 1.6% (IQR 3.95), CD8 1.4% (IQR 3.57). PD-L1 was positive for IC and TC in 40.2% (35/138) and 9.2% (8/138) of patients, respectively. TILs, CD3, CD8 and PD-L1 were significantly associated with G3, Ki67 and negative RE (p <0.05). HER2 phenotype had the highest percentage of TILs (20%, IQR 43.5), CD3 (14%, IQR 23.65) and CD8 (8.4%, IQR 14.7), followed by Triple Negative (TN) (TILs 10% IQR 48.5; CD3 5% IQR 20.8; CD8 2%, IQR 12.8) and luminal type (TILs 1,5% IQR 4; CD3 0.97% IQR 3.8; CD8 0.92%, IQR 3.3). PD-L1_ic expression was higher in TN (PD-L1 ic 3.5%, IQR 25) followed by HER2 (PD-L1 ic 2%, IQR 20) and it had minimal expression in luminal. The expression of PD-L1_tc was significantly higher in HER2 phenotype (PD-L1_tc 0.5%, RQI 1.75) followed by TN (0.5%, IQR 1). Luminal phenotype did not show PD-L1_tc expression.
Conclusions
TILs, CD3, CD8 and PDL1 expressions were significantly associated with worse prognosis phenotypes. HER2 and TN phenotypes presented more TILs and PD-L1 expression than luminal samples. This suggests a greater influence of the immune system in the development of HER2 and TN breast cancer.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
A. Rueda Dominguez: Financial Interests, Institutional, Advisory Role: MERCK; Financial Interests, Institutional, Advisory Role: BMS; Financial Interests, Institutional, Advisory Role: ROCHE; Financial Interests, Institutional, Speaker’s Bureau: MERCK; Financial Interests, Institutional, Speaker’s Bureau: BMS; Financial Interests, Institutional, Speaker’s Bureau: ROCHE; Financial Interests, Institutional, Speaker’s Bureau: TAKEDA. All other authors have declared no conflicts of interest.