CD274 and neoplasm: PD-L1 positivity in primary or metastatic tumours was not associated with post-recurrence survival (PD-L1 positivity in primary tumours: HR, 0.92; 95% CI, 0.47–1.82; p = 0.81; PD-L1 positivity in metastases: HR, 0.23; 95% CI, 0.038–1.35; p = 0.10).