Prognostic value of miR17-92 family in patients with digestive system cancers: a systematic review and meta-analysis

The miR17-92 family is found to be aberrantly expressed and associated with clinicopathological characteristics in patients with various cancers, including digestive system cancers. However, its prognostic value is not yet established. Therefore, we performed a systematic review and meta-analysis to investigate the association between miR17-92-family expression and clinical outcomes in digestive system cancers. We searched the PubMed, Web of Science, Embase, and CNKI (Chinese) databases to retrieve eligible studies up to June 30, 2018. Prognostic data and clinicopathological features of overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS) were extracted to evaluate correlations of the miR17-92 family with digestive system cancers. We used HRs to assess association between miR17-92-family expression and cancers prognosis. A total of 30 qualifying studies involving 4,056 subjects were included in this meta-analysis. Our results indicated that expression levels of miR17-92 can predict poor OS (HR 1.21, 95% CI 1.03–1.39; P=0). However, there was no relationship between the miR17-92 family and DFS (HR 0.86, 95% CI 0.6–1.11; P=0.170) or PFS (HR 1.37, 95% CI 0.83–1.91; P=0). Moreover, miR17-92 was related to TNM stage (III/IV vs I/II, HR 1.37, 95% CI 1.17–1.570; P=0.012), but there was no relationship between miR17-92 and metastasis (HR 1.64, 95% CI 1.34–1.95; P=0.491) or tumor size (≥5 cm vs <5 cm, HR 1.29, 95% CI 1.09–1.49; P=0.586). Subgroup analysis showed that miR17-92 expression was associated with poor OS among the Chinese subgroup (HR 1.28, 95% CI 1.08–1.48; P=0) and tissue samples (HR 1.12, 95% CI 0.93–1.31; P=0), while there was no association with other characteristics. Our results indicated that miR17-92 expression is significantly associated with poor survival in patients with digestive system cancers, suggesting that miR17-92 may be a promising prognostic marker to monitor prognosis and progression of cancers.