The prognostic role of the cancer stem cell marker CD44 in ovarian cancer: a meta-analysis

Background: CD44 has recently been reported as a cancer stem cell marker in ovarian cancer. However, the clinicopathological and prognostic value of this marker in ovarian cancer remains controversial; Here, we aimed to investigate the correlation between CD44 expression and the clinicopathological features or survival of ovarian cancer patients. Methods: An extensive literature search in the PubMed, EMBASE, and Wanfang databases (up to June 1, 2016) was conducted to identify studies that assessed the clinical or prognostic significance of CD44 expression in ovarian cancer. A meta-analysis was then performed to clarify the association between CD44 expression and clinical outcomes of ovarian cancer patients. Results: A total of 18 publications consisting of 2161 patients were included for this meta-analysis. Our data reveal that CD44-positive expression in ovarian cancers were significantly associated with a high TMN stage (pooled OR = 2.11, 95% CI 1.26-3.53, P = 0.004) and poor 5-year overall survival (RR = 1.42, 95% CI 1.01-2.00, P = 0.05). However, CD44 expression was not associated with tumor grade, lymphatic metastasis, age of the patients, residual tumor size, response to chemotherapy, or ascites volume (P > 0.05). Conclusion: Detection of CD44 may be an effective tool for pathological diagnosis and prognostic prediction of ovarian cancer patients in clinical applications.