Dietary impacts on prostate cancer immunotherapy

Prostate cancer is a leading cause of cancer-related mortality in men. While early-stage disease is readily treated, advanced-stage prostate cancer has a poor survival rate and limited effective therapies. Immunotherapy has achieved significant success in other malignancies, but prostate cancer is characterized by an immunosuppressive, "cold" tumor microenvironment that blunts immunotherapy efficacy. Emerging evidence suggests that dietary interventions - such as ketogenic diets, methionine restriction, and bioactive compounds like white button mushroom extract - can modulate the tumor microenvironment and enhance immunotherapy responses in preclinical and early clinical studies. Additionally, specific diet-derived factors (such as the ketone body β-hydroxybutyrate) have demonstrated anti-tumor immune effects on their own, representing new avenues for combination therapy. While prior reviews have addressed diet or immunotherapy in prostate cancer independently, this review integrates these domains with the aim of offering a streamlined perspective. This brief review synthesizes recent findings on dietary modulation of prostate cancer immunity, with a focus on mechanistic insights that may be leveraged to augment immunotherapy, to suggest potential combination strategies and inform future translational efforts.