Prognostic value of circulating microRNA-21 for breast cancer: a systematic review and meta-analysis

Abstract

Background: There is an urgent need for novel noninvasive prognostic molecular tumor marker for monitoring the recurrence of breast cancer. MicroRNA-21 (miR-21) play a crucial role in the progression and aggressiveness of breast cancer, but its prognostic significance for patients with breast cancer remains inconclusive. The aim of this meta-analysis is to summarize the role of circulating miR-21 as a molecular marker in patients with breast cancer.

Material and methods: Eligible studies were searched from the PubMed, EMBASE and Web of Science databases. The χ² and I² tests were used to evaluate heterogeneity between studies. The pooled hazard ratios (HR) with 95% confidence interval (CI) were calculated by a fixed-effects model, if no heterogeneity existed. If there was heterogeneity, a random-effects model was applied. The meta-analysis was conducted using the Review Manager 5 software.

Results: A total of 7 articles which included 1629 cases were selected for the meta-analysis. Elevated miR-21 expression was significantly predictive of poor overall survival (HR = 1.51, 95%CI 1.15–1.98, p = 0.003). The subgroup analysis consisted of in tissue sample (HR = 1.66, 95%CI 1.03–2.67, p = 0.04) and serum sample (HR = 1.73, 95%CI 1.22–2.46, p = 0.002). The association between miR-21 expression level and lymph node metastasis was statistically significant (OR = 2.36, 95%CI 1.04–4.78, p = 0.03).

Conclusion: Our findings suggest that the circulating miR-21 expression level can predict poor prognosis in patients with breast cancer.

Keywords:

• Circulating miR-21
• breast cancer
• prognostic
• meta-analysis

Disclosure statement

The authors declared that they had no conflict of interest.