Immunity, Age, and Luminal Breast Cancer: Understanding the Holy Trinity

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• Hormone-receptor-positive/HER2-negative breast cancer is the most common subtype.
• Tumor-infiltrating lymphocytes (TILs) are immune cells within tumors that can influence cancer progression.
• The prognostic role of specific TIL subtypes in this breast cancer subtype requires further elucidation.

Purpose of the Study:

• To investigate the association between various TILS subtypes and clinical outcomes in patients with stage I-III hormone-receptor-positive/HER2-negative breast cancer.
• To determine if immunostimulatory and immunosuppressive TILs have differential impacts on survival.

Main Methods:

• Retrospective analysis of 390 patients with stage I-III hormone-receptor-positive/HER2-negative breast tumors.
• Quantification of TILs subtypes, including T-regulatory cells and CD8- and non-CD8 T-cells, via immunohistochemistry.
• Correlation of TILs counts with distant disease-free survival and overall survival at 8-year follow-up.

Main Results:

• A higher number of total TILs subtypes was significantly associated with improved distant disease-free survival.
• Both immunostimulatory and immunosuppressive TILs subtypes, including T-regulatory cells and CD8- and non-CD8 T-cells, were linked to better overall survival.
• The presence of diverse TILs populations, irrespective of their immune function, indicates a favorable prognosis.

Conclusions:

• TILs subtypes are significant prognostic biomarkers in early-stage hormone-receptor-positive/HER2-negative breast cancer.
• The composition of the tumor immune microenvironment, characterized by various TILs, plays a crucial role in predicting patient outcomes.
• These findings support the potential utility of TILs assessment in clinical decision-making for this patient group.