Chemohormonal Therapy Remodels Prostate Cancer Immune Microenvironment and Enhances Checkpoint Inhibitor-based immunotherapy

Checkpoint blockade immunotherapy is a promising strategy in cancer treatment, depending on a favorable preexisting tumor immune microenvironment. However, prostate cancer is usually considered as an immune “cold” tumor with the poor immunogenic response and low density of tumor-infiltrating immune cells. This research uses samples from prostate cancer patients showing that docetaxel-based chemohormonal therapy reprograms the immune microenvironment and increases tumor-infiltrating T cells. Mechanistically, docetaxel treatment activates the cGAS/STING pathway and induces the type I interferon signaling, which may boost T cell-mediated immune response. In a murine prostate cancer model, chemohormonal therapy sensitizes tumor-bearing mice to PD1-blockade therapy. These findings demonstrate that docetaxel-based chemohormonal therapy activates prostate cancer immunogenicity and acts cooperatively with anti-PD-1 checkpoint blockade, providing a combination immunotherapy strategy that would lead to better therapeutic benefit for prostate cancer. Overall design: mRNA profiles of 11 paired pre- and post-chemohormonal therapy prostate cancer samples