The Prognostic Value of Platelet-to-Lymphocyte Ratio in Urological Cancers: A Meta-Analysis

The relationship of platelet-to-lymphocyte ratio (PLR) and survival in urological cancers remained inconsistent in previous studies. Therefore, we performed a meta-analysis to assess the prognostic significance of PLR in patients with urological cancers. A literature search was performed in the PubMed, Embase, and Web of Science up to July, 2017 and study quality was obtained using the Newcastle-Ottawa Scale. To estimate the association of PLR and overall survival (OS) and other survival outcomes in urological cancers, we used pooled hazard ratios (HRs). Subgroup analyses were conducted on different ethnics, sample sizes and cut-off values. 20 high quality studies involving 7562 patients with urological cancers were included in this meta-analysis. High pretreatment PLR was significantly associated with poor OS in patients with urological cancers (pooled HR = 1.58). Elevated PLR was also correlated with other survival outcomes. However, we found that PLR was significantly relevant to the OS of patients with different types of urological cancers except bladder cancer (BCa, HR = 1.16, 95%CI: 0.96-1.41). In conclusion, elevated PLR was negatively related to the OS of patients with urological cancers, except in BCa. However, more large scale prospective studies with high quality are required in the future.