Prognostic significance of platelet-to-lymphocyte ratio in urothelial carcinoma patients: a meta-analysis

BACKGROUND: The prognostic value of pre-treatment platelet-to-lymphocyte ratio (PLR) in patients with urothelial carcinoma (UC) remains controversial. Therefore, this meta-analysis aimed to identify the prognostic impact of PLR on UC. METHODS: The PubMed, Embase, Web of Science, and Cochrane Library databases were systematically searched. Hazard ratios (HRs) with 95% confidence intervals (CIs) were used to summarize the correlations between PLR and overall survival (OS), progression-free survival (PFS), disease-free survival (DFS), and cancer-specific survival (CSS). Odds ratios (ORs) with 95% CIs were used to measure the association between PLR and tumor clinicopathological factors. RESULTS: The meta-analysis included 15 studies published from 2015 to 2019 with a total of 5354 patients. Overall, a high PLR was correlated to poorer PFS (HR = 1.81, 95% CI 1.28–2.56, p = 0.001) and DFS (HR = 1.09, 95% CI 1.31–2.16, p < 0.001) but not poor OS (HR = 1.23, 95% CI 0.95–1.59, p = 0.124) or CSS (HR = 1.000, 95% CI 0.998–1.002, p = 0.919) in UC. In addition, an elevated PLR was correlated with patient age > 65 years (OR = 1.72, 95% CI 1.25–2.38, p = 0.001) and hypertension (OR = 1.48, 95% CI 1.01–2.18, p = 0.046). However, no significant association was observed between PLR and sex (OR = 0.79, 95% CI 0.56–1.14, p = 0.206) or diabetes (OR = 1.29, 95% CI 0.77–2.15, p = 0.333). CONCLUSIONS: Our results demonstrated a significant correlation between elevated PLR and poor prognosis in UC. The prognostic role of PLR may help guide the management and prognostication of UC patients.