The evaluation of monocyte lymphocyte ratio as a preoperative predictor in urothelial malignancies: a pooled analysis based on comparative studies

In recent years, several studies have reported monocyte lymphocyte ratio (MLR) to predict prognosis in various tumors. Our study was performed to evaluate the association between preoperative MLR between prognostic variables in urothelial carcinoma patients. Systematic literature search was conducted in PubMed, Embase, Web of science. The correlation between preoperative MLR and overall survival (OS), cancer specific survival (CSS), disease free survival (DFS)/relapse free survival (RFS), progression free survival(PFS) was evaluated in urothelial carcinoma patients. Meanwhile, the association between MLR and clinicopathological characteristics was assessed. Finally, 12 comparative studies comprising a total of 6209 patients were included for pooled analysis. The hazard ratios (HRs), odds ratios (ORs)and 95% confidence intervals (CIs) were further analyzed as effect measures. The pooled results demonstrated that elevated preoperative MLR indicated unfavorable OS (HR = 1.29, 95%CI = 1.18-1.39, I(2) = 33.6%), DFS/RFS (HR = 1.42, 95%CI = 1.30–1.55, I(2) = 0.0%) and CSS (HR = 1.41, 95%CI = 1.29–1.52, I(2) = 0.0%). Moreover, the pooled results also suggested that elevated preoperative MLR was correlated with high tumor stage (OR = 1.22, 95%CI = 1.07–1.37, I(2) = 0.0%) in urothelial carcinoma patients. No significant association was found between preoperative MLR and PFS in upper urinary tract urothelial carcinoma (UUTUC) patients. Collectively, elevated preoperative MLR predicted poor prognosis in urothelial carcinoma and have the potential to be a feasible and cost-effective prognostic predictor for management of urothelial carcinoma.