PARP Inhibitors and the Risk of Serum Creatinine Elevation in Ovarian Cancer: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Poly(ADP-ribose) polymerase inhibitors (PARPis) are established maintenance therapies in epithelial ovarian cancer (EOC). Although considered relatively safe, their impact on renal function remains unclear. Increases in serum creatinine (SCr) are frequently observed during treatment, but the clinical significance of these changes is uncertain. We conducted a systematic review and meta-analysis to assess the risk of renal adverse events associated with PARPis in randomized controlled trials (RCTs). Methods: PubMed/MEDLINE, Embase, and the Cochrane Library were searched for phase II–III, placebo-controlled RCTs published through 30 June 2025. Eligible studies enrolled patients with ovarian cancer receiving maintenance monotherapy with olaparib, niraparib, rucaparib, or fuzuloparib and reported renal adverse events. The primary endpoint was creatinine increase (all grades). Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed- or random-effects models according to heterogeneity. Results: Nine high-quality RCTs comprising 2578 patients met the inclusion criteria. PARPi therapy was associated with a significantly increased risk of creatinine elevation compared with placebo (OR 5.04; 95% CI 3.51–7.24; p < 0.001). Heterogeneity was moderate (I2 = 31.7%). High-grade renal adverse events (≥grade 3) were rare (<1%) and could not be reliably pooled. No significant publication bias was detected. Conclusions: PARP inhibitors significantly increase the likelihood of SCr elevation in EOC; however, severe nephrotoxicity appears uncommon in RCTs. Observed SCr increases may partly reflect inhibition of renal tubular creatinine transport rather than true reductions in glomerular filtration. Careful renal monitoring and prospective studies incorporating direct GFR assessment are warranted.