Title:Neoadjuvant Endocrine Therapy: A Potential Way to Make Cold
Hormone Receptor-Rich Breast Cancer Hot
Volume: 26
Issue: 5
Author(s): Yinan Wu, Xiaonan Gong, Kaiyue Wang, Chengcheng Yu, Jili Qiu, Suzhan Zhang*, Yue Hu*Kaimin Hu*
Affiliation:
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National
Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province), The Second Affiliated
Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang, China
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang, China
- Department of Breast Surgery, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang, China
- Cancer Institute (Key Laboratory of Cancer Prevention and Intervention, China National
Ministry of Education, Key Laboratory of Molecular Biology in Medical Sciences, Zhejiang Province), The Second Affiliated
Hospital, Zhejiang University School of Medicine, Hangzhou 310009, Zhejiang, China
Keywords:
HR+ BCs, immune infiltrating, endocrine therapy, predictive marker, immunotherapy, EMT.
Abstract:
Background: Turning the “cold” tumor immune microenvironment into “hot” is a critical
issue in cancer treatment today. Hormone receptor-rich breast cancer (HR+ BC) was previously
considered immunologically quiescent.
Objective: This study aims to explore the immunomodulatory effects of endocrine therapy on HR+
BCs.
Methods: The infiltrations and alterations of the tumor immune microenvironment in HR+ BCs before,
after 10-14 days, and after three months of neoadjuvant endocrine therapy were computationally
analyzed according to MCP-counter, CIBERSORT, xCell algorithms, and gene-set enrichment
analysis (GSEA). The primary microarray data were obtained from three HR+ BC gene expression
datasets (GSE20181, GSE55374, and GSE59515). Single-sample GSEA of hallmark and immune
response gene sets was performed to evaluate the correlation between suspected treatment response
and activated immune pathways in tumors.
Results: Both immune and stromal cells were specifically recruited into the HR+ BCs who responded
to the neoadjuvant endocrine therapy by letrozole. Besides the enhanced infiltrations of
immunosurveillance-related cells such as CD8+ T cells, dendritic cells, and the activation of immune
response-related signals, the immunosuppressive M2-like macrophages, as well as the expression
of immune checkpoint genes like PDCD1, SIRPA, and some HLA genes, were also stimulated
in responders. We identified four pretreatment indicators (the intrinsic luminal subtype, the
estrogen response early/late pathway, and the epithelial-mesenchymal transition pathway) as
potential predictors of both clinical response and the activation of the tumor immune microenvironment
post letrozole.
Conclusion: Neoadjuvant endocrine therapy showed a promising way to convert the immunologically
“cold” HR+ BCs into “hot” tumors. This study provides new insights into the application of
immunotherapy for HR+ BCs, especially those who respond to endocrine therapy.