BackgroundThe purpose of this comprehensive meta-analysis was to assess the association of aldehyde dehydrogenase (ALDH) expression with overall survival (OS) and disease-free survival (DFS)/progression-free survival (PFS) in ovarian cancer patients.MethodsSystematic searches of Pubmed databases was performed to identify relevant literature published before February 28, 2018. A total of 14 studies (13 articles) with 2210 ovarian cancer patients were pooled. All included studies were performed by using Immunohistochemistry (IHC) for detection of ALDH expression. Hazard ratio (HR) and 95% confidence interval (CI) were extracted from included studies to evaluate the correlation of ALDH expression with OS and DFS/PFS.ResultsHigh expression of ALDH was associated with worse OS (HR: 1.43; 95% CI: 1.18-1.73) and poor DFS/PFS (HR: 1.55, 95% CI: 1.12-2.14). No evidence of publication bias was observed in OS (Begg's test, P=0.113; Egger's test, P=0.355) and DFS/PFS (Begg's test, P=0.655; Egger's test, P=0.189) in ovarian cancer patients. The subgroup of studies with cut-off value of low expression showed that high expression of ALDH was correlated with poor OS (HR: 1.36; 95% CI: 1.14-1.62) and DFS/PFS (HR: 1.79; 95% CI: 1.45-2.20) in ovarian cancer patients, with no observed heterogeneity (OS: I-2=0%, P=0.45; DFS/PFS: I-2=0%, P=0.55).ConclusionIn conclusion, high expression of ALDH is correlated with worse survival profiles in ovarian cancer patients, indicating that ALDH might act as a potential molecular biomarker for prognosis of ovarian cancer.