The role of lactate deshydrogenase levels on non-small cell lung cancer prognosis: a meta-analysis.

The role of serum lactate dehydrogenase (LDH) on the clinical outcomes of non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKIs) treatment remained to be elucidated. Therefore, we did this meta-analysis. We searched databases including PubMed, EMBASE, and Cochrane Library till to June, 2017. The relationships between the LDH levels and overall survival (OS) and progression free survival (PFS) were assessed by calculating hazard ratios (HRs) and 95% confidence intervals (CIs). The association between the LDH levels and disease control rate (DCR) was calculated by odds ratio (OR) and 95% CI. Seven studies were included in the meta-analysis. As for DCR, the result from this meta-analysis was not positive (OR=0.71; 95% CI 0.21 - 2.37; P=0.57). As for PFS, the result of the meta-analysis indicated that elevated LDH was significantly associated with shorter PFS (HR=1.88; 95%CI, 1.37-2.59). When studies were stratified by ethnicity, significant association was also observed in Asian group (HR=2.36; 95%CI, 1.57-3.55). As for OS, patients with high levels of LDH showed significantly shorter OS (HR=2.44; 95%CI, 1.84-3.23). In the subgroup by race, significant associations were found in Asian group (HR=2.62; 95%CI, 1.61-4.26) and Caucasian population (HR=2.36; 95%CI, 1.66-3.34). In conclusion, this meta-analysis suggested that elevated LDH level was associated with the poor PFS and OS of NSCLC patients receiving EGFR-TKIs treatment.