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

OBJECTIVE: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.