Platelet-lymphocyte ratio acts as an independent predictor of prognosis in patients with renal cell carcinoma

Background: The prognostic value of plated-lymphocyte ratio (PLR) in multiple malignancies had been investigated in previous studies; however, its prognostic value in renal cell carcinoma (RCC) remains controversial. This study was performed to assess the prognostic value of preoperative PLR in RCC patients. Methods: Literature was searched from PubMed, Embase, Web of Science and Cochrane database, which evaluated the relationships between preoperative PLR and prognosis in RCC patients. Hazard ratios (HRs) for overall survival (OS) and progression-free survival (PFS) were extracted from eligible studies. Heterogeneity was assessed using the I-2 value. The fixed-effects model was used if there was no evidence of heterogeneity; otherwise, the random-effects model was used. Publication bias was evaluated using Begg's funnel plots and Egger's regression test. Results: A total of 1528 patients from seven studies were included in the analysis. The pooled analysis showed that an elevated PLR was an effective prognostic marker of both OS (pooled HR = 2.10, 95%CI: 1.38-3.19, p = 0.001) and PFS (pooled HR = 3.45, 95%CI: 1.61-7.40, p = 0.001). Subgroup analysis revealed that a high PLR significantly predicted worse OS and PFS in Asian studies (OS, pooled HR = 2.72, 95%CI: 1.06-7.03, p = 0.038; PFS, pooled HR = 6.0, 95%CI: 3.12-11.54, p < 0.001), in metastatic RCC patients receiving mixed therapies (OS, pooled HR = 3.69, 95%CI: 1.93-11.42, p = 0.023; PFS, pooled HR = 6.05, 95%CI: 1.34-27.37, p = 0.019) and targeted therapy (OS, pooled HR = 1.59, 95%CI: 0.97-2.62, p = 0.067), in sample size > 100 (OS, pooled FIR = 1.83, 95%CI: 1.49-2.25,p < 0.001; PFS pooled HR = 6.05, 95%CI: 1.34-27.37, p < 0.019), and in cut-off value of PLR <= 195 (OS, pooled HR = 3.65, 95%CI: 1.06-12.60, p = 0.04; PFS pooled HR 4.46, 95%CI: 1.68-11.87, p = 0.003). Conclusions: This study suggests that a high preoperative PLR is correlated with poor prognosis in RCC patients.