Background The prognostic nutritional index (PNI) has been associated with survival outcomes in multiple solid tumors, yet its prognostic relevance in prostate cancer patients undergoing androgen deprivation therapy (ADT)-based systemic treatment remains insufficiently characterized. Methods We systematically searched PubMed, Embase, Cochrane Library, Web of Science, and China National Knowledge Infrastructure (CNKI) from database inception to September 11, 2025. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to assess the association between PNI and survival outcomes; pooled odds ratios (ORs) with 95% CIs evaluated links with clinicopathological features. Subgroup analyses explored heterogeneity sources. Results Ten retrospective studies involving 1, 847 patients were included. Low PNI was significantly associated with worse overall survival (HR = 2.082, 95% CI: 1.756–2.469, p 0.001). Due to heterogeneous definitions of disease progression across studies, progression-related endpoints were analyzed separately by type. Low PNI consistently predicted inferior outcomes across multiple progression-free survival metrics: PFS (HR = 1.606, 95% CI: 1.328–1.942), radiographic PFS (rPFS; HR = 2.315, 95% CI: 1.525–3.514), and PSA-PFS (HR = 3.176, 95% CI: 2.169–4.652) (all p 0.001). Subgroup analyses supported result robustness. Additionally, low PNI correlated significantly with Gleason score 7 (OR = 1.404, p = 0.018), bone metastasis (OR = 1.433, p = 0.015), LATITUDE high-risk status (OR = 1.898, p = 0.003), and CHAARTED-defined high tumor burden (OR = 1.950, p = 0.001), but not with age, visceral metastases, or EAU high-risk classification. Conclusions In the context of ADT-based systemic therapy, low PNI is a significant predictor of poor survival and aggressive disease features, supporting its potential as a readily available biomarker for risk stratification and prognostic assessment in prostate cancer patients. Systematic review registration https://www.crd.york.ac.uk/prospero/ , identifier CRD420251145397.
Huang et al. (Tue,) studied this question.