Prevalence and prognostic role of PD-L1 in patients with gynecological cancers: A systematic review and meta-analysis

Our study aims to evaluate programmed cell death ligand-1 (PD-L1) expression and its prognostic significance in cervical cancer (CC), endometrial cancer (EC) and ovarian cancer (OC). Several electronic databases were searched. Fixed effects models or random effects models were employed to calculate the pooled prevalence of PD-L1 positivity and pooled hazard ratios (HRs) as appropriate. Heterogeneity and publication bias were also assessed. The pooled prevalence of PD-L1 positivity was 58.1%, 33.8% and 37.5% for CC, EC and OC patients, respectively. There were significant differences in the pooled estimates after stratification by PD-L1-positive assessment criteria and antibody clones. PD-L1 positivity was associated with worse OS in CC and EC patients and poorer progression-free survival (PFS) in CC patients. The prevalence of PD-L1-positive expression was considerably high in CC and modestly high in EC and OC patients. PD-L1 expression has the potential to be a prognostic biomarker for predicting the clinical outcomes of patients with CC and EC but not OC.