CD274 and cancer: There was no interaction between cancer cite and the association of PD-L1 expression with OS or specific survival, although longer survival was observed in patients with oropharyngeal and hypopharyngeal cancers, with pooled aHRs of 0.70 (95% CI, 0.58-0.85) for OS and 0.80 (95% CI, 0.68-0.95) for specific survival.