Patterns of immune infiltration and survival in endocrine therapy-treated ER-positive breast cancer: A computational study of 1900 patients

Abstract

Tumor-infiltrating immune cells (TIICs) play a critical role in breast cancer (BC) prognosis, but little is known regarding the efficacy of endocrine therapy in patients with ER-positive BC with diverse immunological phenotypes. To investigate whether TIICs affect survival after endocrine therapy in patients with different BC molecular subtypes, data were gathered from six studies totaling 1900 samples. CIBERSORTx was used to analyze the invasion of 22 immune cell subpopulations using a bulk gene expression profile. The relationships of immune-related metagenes and immune cell subsets with survival (distant metastasis-free survival, relapse-free survival, and overall survival) were studied using Cox regression models with cell proportions modeled in quartiles. The immune score and IGHG3 and LCK gene activity were linked to a better prognosis. Among the immune cells, monocytes, resting CD4+ memory T cells and plasma cells were correlated with prolonged survival, while neutrophils, Tregs, M0 macrophages, and M2 macrophages were associated with an unfavorable prognosis. Similar effects were reported for the luminal A subtype. In the luminal B subtype, γδ T cells and eosinophils were favorable prognostic factors. Covariate-adjusted multivariate Cox regression analysis revealed that high proportions of resting CD4+ memory T cells and resting dendritic cells were correlated with a good prognosis. Meanwhile, neutrophils were associated with an unfavorable prognosis. Understanding how monocytes and macrophages interact in the tumor microenvironment may be a promising study focus. Comprehensive research on the cellular immune response in tumors could help facilitate the development of new treatments.

Keywords

• Tumor immune infiltration
• ER+ breast cancer
• Survival
• Endocrine-treated
• Biomarker
• Molecular subtypes