Immune environment of high-TIL breast cancer: triple negative and hormone receptor positive HER2 negative.

ABSTRACT: This study explores differences in immune cell (IC) composition and spatial distribution between triple-negative breast cancer (TNBC) and hormone receptor-positive, HER2-negative breast cancer (HR + HER2-BC) in high-TIL (≥60%) cases, focusing on PD-L1 status. Using multiplex immunofluorescence on resected tumor tissues from 18 TNBC and 14 HR + HER2-BC cases, we analyzed IC types (CD20, CD8, CD4, FOXP3) and their spatial interactions. TNBC showed a unique IC composition characterized by a higher proportion of CD8 + IC (stroma: 27% vs 17%, p < 0.001; tumor: 54% vs 31%, p < 0.001) and CD4 + FOXP3 + IC (stroma: 3.9% vs 3.0%, p = 0.036), compared to HR + HER2-BC. Notably, PD-L1 positive TNBC cases demonstrated denser infiltration CD4 + FOXP3 + IC in the stromal region compared to HR + HER2-BC (

SUBMITTER: Shin SJ 

PROVIDER: S-EPMC11599379 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature