CD274 and renal cell carcinoma: A systematic literature review including observational studies worldwide reporting the OS of patients receiving conventional first-line pharmacological therapy for advanced/metastatic non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), or melanoma in the anti-PD-(L)1 pre-approval era and similar patients receiving first-line anti-PD-(L)1 therapy in the post-approval era was conducted.