microRNA-210 as a prognostic factor in patients with breast cancer: Meta-analysis

BACKGROUND: microRNA-210 expression in breast carcinoma represents an appealing prognostic tool, but no consensus exists on this debating topic. OBJECTIVE: We conducted this comprehensive meta-analysis to summarize evidence for use of microRNA-210 to predict patients' clinical outcomes. METHODS: Relevant literatures were identified using Pubmed and EMBASE. Patients' clinical characteristics and survival related data were extracted. Statistics extracted from Kaplan-Meier survival curves were calculated with methods developed by Parmar, Williamson, and Tierney, multivariate Cox hazard regression analysis data were used directly in Revman 5.0. Pooled hazard ratios (HRs) were calculated to evaluate the prognostic role of microRNA-210. RESULTS: Finally, 7 studies containing 822 patients were considered eligible, pooled HR (95% CI) of studies for overall survival was 3.94 (1.90-8.15), for disease/recurrence free survival was 3.47 (2.63-4.60) and for metastasis free survival was 2.70 (1.46-5.00). We then respectively grouped the meta-analysis by patients' region (Asia and non-Asia), tumor estrogen receptor/progesterone receptor/Her-2 expression status (positive or negative) and treatment strategy (preoperative systemic treatment or only surgery). All the subgroup analysis showed stable prognostic value. CONCLUSIONS: Over-expressed microRNA-210 demonstrated a significantly higher risk of recurrence, metastasis and overall decreased survival rates for breast cancer patients.