Prognostic role of miR-200c in various malignancies: a systematic review and meta-analysis

MiR-200c expression is dysregulated in various malignancies and may predict the survival of patients with cancer, although the results of different studies conflict. Therefore, we conducted a meta-analysis to resolve this discrepancy. We queried the PubMed and Embase using multiple search strategies. Data were extracted from studies comparing overall survival and progression-free survival in patients with cancer with high and low levels of miR-200c expression. Fixed and random models were used where appropriate. A combined hazards ratio (HR) was calculated to estimate the association of high levels of miR-200c with survival. We selected 16 studies of 1485 participants for our final meta-analysis. Upregulated expression of miR-200c predicted significantly worse overall survival in patients with cancer (HR 1.51; 95% confidence interval [CI] 1.06-2.16, P = 0.023). Subgroup analysis indicated that high levels of miR-200c was associated with decreased survival of Caucasians and patients with gynecological tumors with pooled HR values of 1.82 (95% CI 1.27-2.26, P = 0.01) and 3.23 (95% CI 1.11-9.38, P = 0.032), respectively. Because of the absence of apparent heterogeneity, the combined HRs were 1.69 (95% CI 1.24-2.30, P = 0.001) for squamous cell carcinoma and 1.91 (95% CI 1.40-2.59, P < 0.001) for samples from peripheral blood. Increased expression of miR-200c significantly associated with shorter progression-free survival of patients with cancer (HR 2.37; 95% CI 1.47-3.81, P < 0.001). Our meta-analysis indicates that the level of miR-200c expression predicted survival of patients with cancer, particularly for Caucasians and patients with gynecological cancer. Increased expression of miR-200c predicted shorter survival of patients with squamous cell carcinomas. Our findings indicate that monitoring the levels of miR-200c in blood may be useful for following tumor progression as well as patients' prognosis.