Higher pretreatment lactate dehydrogenase concentration predicts worse overall survival in patients with lung cancer

Background: The aim of this study was to systematically evaluate the prognostic role of pretreatment lactate dehydrogenase (LDH) concentration for survival in patients with lung cancer through performing a meta-analysis. Methods: PubMed, EMBASE, Cochrane Library, Web of Science, and China National Knowledge Infrastructure were searched for potentially relevant literature. The study and patients' characteristics were extracted. Hazard ratios (HRs) with 95% confidence intervals (95% CIs) were pooled to estimate the prognostic role of LDH in patients with lung cancer. Results: Fourteen studies with 4084 patients were included. Higher pretreatment LDH concentration was significantly associated with an increased risk of overall mortality in patients with lung cancer (HR=1.49, 95% CI, 1.38-1.59). Subgroup analysis of studies also resulted in a significantly increased risk of mortality in patients with small cell lung cancer (SCLC, HR=1.54, 95% CI, 1.43-1.67) or nonsmall cell lung cancer (NSCLC, HR=1.25, 95% CI, 1.06-1.46), with high pretreatment LDH concentration. No significant between-study heterogeneity was observed (I-2=12.0%, P=.321). No significant publication bias was found (P=.352) in the meta-analysis. Conclusion: The results suggested that higher pretreatment LDH concentration was associated with worse overall survival in patients with lung cancer. The findings may assist future research on anticancer therapy by targeting LDH and help predict prognosis in lung cancer patients. However, high-quality studies are required to further research and support these associations. Moreover, confounding factors such as patient ethnicity and tumor type should be considered in future studies.