Clinicopathological and prognostic values of ALDH1 in epithelial ovarian cancer: a meta-analysis

Background: Previous studies have confirmed the prognostic value of positive aldehyde dehydrogenase 1 (ALDH1) expression for ovarian cancer, but its predictive value remains controversial. Methods: Meta-analysis was conducted to clarify the correlation of positive ALDH1 expression with the clinicopathological characteristics, types, overall survival and progression-free survival of epithelial ovarian cancer. PubMed, EMBASE and Cochrane were comprehensively searched through July 2017. Nine studies were included. Results: High ALDH1 expression was significantly correlated with the International Federation of Gynecology and Obstetrics (FIGO) stage of ovarian cancer in both Chinese and Caucasians, and with tumor grade in Chinese people (pooled OR and 95% CI = 2.10 (1.20, 3.67)), but not with lymph node metastasis (2.47 (0.77, 7.87)) or tumor location in the ovary (1.10 (0.62, 1.96)). ALDH1 expression was correlated with subtypes of epithelial ovarian cancer (e.g. serous carcinoma, mucinous carcinoma and endometrioid carcinoma) in Caucasians and with the overall survival (1.59 (1.11, 2.29)), but not with progression free survival (1.14 (0.72, 1.82)). Conclusions: Positive ALDH1 expression is significantly correlated with the clinicopathological characteristics and prognosis of ovarian cancer.