MicroRNA-21 as a Prognostic Biomarker in Patients with Pancreatic Cancer – A Systematic Review and Meta-Analysis

Abstract Objectives The aim of this systematic review and meta-analysis is to summarize the current knowledge regarding microRNA-21 and to evaluate its prognostic impact in patients with pancreatic cancer. Methods We conducted an electronic literature search to identify all published studies in PubMed/MEDLINE, Scopus and Google Scholar databases from 2000 until August 2016. Results A total of 17 studies involving 1471 patients met the inclusion criteria for the quantitative synthesis. The microRNA-21 upregulation was significantly associated with poorer overall survival, disease-free survival, and progression-free survival. The subgroup analysis revealed that microRNA-21 overexpression has a significant higher prognostic value for patients who receive adjuvant chemotherapy. Increased microRNA-21 was associated with a statistically significant higher rate of metastatic lymph nodes and poorly differentiated tumors. Conclusions MicroRNA-21 upregulation in pancreatic cancer is associated with a significantly poorer overall survival, disease-free survival, and progression-free survival. MicroRNA-21 may be a useful prognostic biomarker, allowing stratification for chemotherapy administration, and being a component of precision medicine in patients with pancreatic cancer.