Prognostic value of prognostic nutritional index in patients with ovarian cancer: a systematic review and meta-analysis

Background: Accumulating evidence indicates an association between the prognostic nutritional index (PNI) and prognosis in patients with ovarian cancer (OC). However, the conclusions drawn from current studies remain controversial. Methods: We performed a systematic literature search in PubMed, Embase, Web of Science, and the Cochrane Library, covering the period from each database's inception up to July 8, 2025, to identify studies investigating the relationship between PNI and clinical outcomes. Eligible studies were identified and selected based on predefined inclusion and exclusion criteria. Primary outcomes included progression-free survival (PFS), overall survival (OS), cancer-specific survival (CSS), and disease-specific survival (DSS), which were quantified using hazard ratios (HR) with their respective 95% confidence intervals (CI). Results: We analyzed thirteen cohort studies involving 5,129 patients. Meta-analysis findings demonstrated an association between reduced PNI and poorer PFS (HR = 1.59, 95% CI: 1.24-2.03; p=0.0002) and curtailed OS (HR = 1.72, 95% CI: 1.36-2.18; p