Why it matters
Hormonal environment shapes immune response:

• Estrogen ↓ T-cell activation;

• Androgen ↓ antigen presentation;

• Their blockade may partially re-sensitize tumors to checkpoint inhibitors.

Clinical snapshot

• Prostate: ADT + PD-1 inhibitors (e.g., pembrolizumab) under investigation — modest benefit in MSI-H or TMB-high tumors only.

• Breast: Few clear synergies; current trials mix AI + ICI for triple-positive tumors.
  (ESMO Immuno-Oncology 2024)

Practical take-away:
Combine only in a clinical trial or guideline-endorsed indication; monitor for immune-endocrine overlap (hepatitis, thyroiditis).