Prognostic value of microRNA-155 in human carcinomas: An updated meta-analysis

miR-155 functions as an oncomiR or as an oncosuppressor-miR in human cancer. Although miR-155 has been researched in many cancers, its prognostic value is uncertain. We performed a literature search in up-to-date electronic databases including PubMed and Embase to obtain as many relevant articles as possible. Combined hazard ratios (HR) of miR-155 for outcome were analyzed. A total of 24 papers researching different cancers were included in this meta-analysis. Combined HRs showed that miR-155 was significantly associated with a poorer OS with HR = 1.99 (1.34–2.96) (I-squared = 83.1%, P = 0.000). Combined HR of PFS/RFS/DFS was 1.95 (1.14–3.33) (I-squared = 75.9%, P = 0.000) and CSS/DSS was 2.50 (0.73–8.58) (I-squared = 87.7%, P = 0.000). Increased miR-155 expression was associated with poorer survival in human carcinoma and as such may be valuable in predicting outcome. •The role of miR-155 in human tumors and its association with prognosis were controversial in previous studies.•The meta-analysis showed that an elevated miR-155 was associated with poor overall survivals in human malignances.•A higher level of miR-155 was related to worse PFS and RFS, but not in DFS and CSS.