title: Prognostic and clinicopathological significance of microRNA-21 overexpression in breast cancer: a meta-analysis.
abstract: Recent studies have highlighted the role of microRNA-21 (miR-21) as a prognostic biomarker of breast cancer. However, controversy still remains. The present study aimed to summarize available evidences and obtain a more precise estimation of a prognostic role of miR-21 in breast cancer patients. All eligible studies were searched from PubMed and EMBASE through multiple search strategies. Data were extracted from studies comparing survival in breast cancer patients having higher miR-21 expression with those having lower expression. A meta-analysis was performed to clarify prognostic role of miR-21 in patients with breast cancer. Subgroup analysis was also performed according to patients' ethnicity. A total of 6 eligible articles comprising 951 cases were selected for this meta-analysis. The combined hazard ratios (HRs) and 95% confidence intervals (95% CIs) for overall survival (OS) were 2.11 (1.09-4.08) and for disease free survival (DFS) was 1.6 (1.30-1.96). Subgroup analysis indicated high miR-21 expression was significantly associated with worse OS in Asian patients (HR = 4.39, 95% CI: 2.47-7.80) but not in non-Asian patients (HR = 1.18, 95% CI: 0.81-1.70). Sensitivity analysis revealed results of this meta-analysis were robust. Odds ratios (ORs) showed that miR-21 expression was closely associated with estrogen receptor (ER), progesterone receptor (PR), lymph node metastasis, histological grade, Her2/neu. The pooled ORs and 95% CIs were 0.53 (0.35-0.80), 0.49 (0.32-0.74), 2.32 (1.54-3.50), 2.44 (1.58-3.75), 4.29 (2.34-7.85), respectively. Our results indicated that elevated miR-21 expression could potentially predict poor survival in patients with breast cancer.
authors.affiliation: Cancer Center, Chinese PLA General Hospital and Chinese PLA Medical School 28 Fuxing Road, Beijing 100853, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Pan
authors.affiliation: Cancer Center, Chinese PLA General Hospital and Chinese PLA Medical School 28 Fuxing Road, Beijing 100853, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
authors.affiliation: National Center for AIDS/STD Control and Prevention, Chinese Center for Disease Control and Prevention Beijing, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Deng
authors.affiliation: School of Bioscience and Bioengineering, South China University of Technology Guangzhou, Guangdong, China.
authors.forename: Guangchao
authors.initials: G
authors.lastname: Li
authors.affiliation: Cancer Center, Chinese PLA General Hospital and Chinese PLA Medical School 28 Fuxing Road, Beijing 100853, China.
authors.forename: Peiliang
authors.initials: P
authors.lastname: Geng
mesh_terms: D044466:Asian People / Q000235:genetics; D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000208:ethnology / Q000235:genetics* / Q000401:mortality / Q000473:pathology / Q000628:therapy; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D035683:MicroRNAs / Q000235:genetics*; D060787:Neoplasm Grading; D016017:Odds Ratio; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D015854:Up-Regulation
chemical_list: D014408:Biomarkers, Tumor; C524940:MIRN21 microRNA, human; D035683:MicroRNAs
keywords: MicroRNA-21; biomarker; breast cancer; meta-analysis; prognosis