<h4>Background</h4>To investigate the potential prognostic role of C-reactive protein to albumin ratio (CAR) in patients with urinary cancers, including renal cell carcinoma (RCC), bladder cancer (BC), and prostate cancer (PC).<h4>Methods</h4>We searched and screened literatures with PubMed, Embase, Cochrane Library, and Web of Science in January 2022. The gene discussed is CRP; the disease is breast cancer.