Prognostic role of pretreatment lactate dehydrogenase in patients with metastatic renal cell carcinoma: A systematic review and meta-analysis

Background: To date, there remain uncertainties over the prognostic role of serum lactate dehydrogenase (LDH) in patients with metastatic renal cell carcinoma (mRCC). A systematic review and meta-analysis was performed. Materials and methods: Eligible studies were retrieved from PubMed, Embase, Cochrane Library and Web of Science databases up to October 2019. The endpoints included overall survival (OS) and progression-free survival (PFS). Multivariable adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were used to evaluate each endpoint. Results: Thirty observational studies of low to moderate risk of bias embracing 6754 patients with mRCC were included. The results showed that patients with a high pretreatment serum LDH had an inferior OS (HR: 2.15, 95% CI: 1.85-2.51; P < 0.001) and PFS (HR: 1.76, 95% CI: 1.49-2.10; P < 0.001). Subgroup analyses according to year of publication, study design, patient population, geographic region, sample size and NOS score did not alter the direction of results. There was significant publication bias for OS, but not for PFS. Sensitivity analyses further confirmed the robustness of the results. Conclusion: Our findings indicated that a high level of pretreatment serum LDH was associated with an inferior OS and DFS in patients with mRCC. Methodological limitations should be considered while interpreting these results.