Systematic review and meta-analysis of the prognostic value of preoperative platelet-to-lymphocyte ratio in patients with urothelial carcinoma

A large number of studies have investigated the prognostic value of the platelet-to- lymphocyte ratio (PLR) in patients diagnosed with urothelial carcinoma, but the evidence from these papers is conflicting. This systematic review and meta-analysis was carried out to assess the role of PLR in urothelial carcinoma patients. After a systematic search of the PubMed, Embase, Web of science databases, the associations between PLR and overall survival (OS), cancer-specific survival (CSS)/disease-specific survival (DSS), and relapse-free survival (RFS)/disease-free survival (DFS) were analyzed in urothelial carcinoma patients. The relationship between PLR and pathological results was also evaluated. A total of seven studies (eight cohorts) comprising 3171 patients were included. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) indicated the increased preoperative PLR predicted poor OS (HR = 1.14, 95% CI = 1.01-1.27, p < 0.001), CSS/DSS (HR = 1.24, 95% CI = 1.08-1.40, p < 0.001), RFS/DFS (HR = 1.23, 95% CI = 1.09-1.38, p < 0.001). However, no significant correlation was found between elevated preoperative PLR and pathological results such as tumor grade, tumor necrosis and T stages. These findings suggest a high PLR is associated with reduced OS, CSS/DSS and RFS/DFS in urothelial carcinoma. Preoperative PLR may therefore be a predictive factor in this patient group.