Clinicopathological and prognostic value of SNHG6 in cancers: a systematic review and a meta-analysis

BACKGROUND: Dysregulation of the long non-coding RNA small nucleolar RNA host gene 16 (lncRNA SNHG6) has been found in multiple cancers. However, a definite conclusion on the clinical value of lncRNA SNHG6 expression in human cancers has not been determined. The purpose of the present meta-analysis was to comprehensively elucidate the association between SNHG6 expression and clinical outcomes in cancers. METHODS: A systematic search was performed through the PubMed, Web of Science, Chinese National Knowledge Infrastructure (CNKI), and Wangfang databases for relevant studies. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were collected to estimate the prognostic value, and the odds ratios (ORs) with 95% CIs were used to evaluate the relationship between lncRNA SNHG6 expression and clinicopathological features, including tumor invasion depth, lymph node metastasis (LNM), distance metastasis (DM), and TNM stage. RESULTS: In total, 914 patients from 13 studies were included in this meta-analysis. The pooled results suggested that evaluated SNHG6 expression could predict an unfavorable overall survival (OS) (HR = 2.04, 95% CI:1.56–2.52) with no heterogeneity (I(2) = 0.0%, p = 0.996). Subgroup analysis indicated a significant association between high SNHG6 expression and shorter OS in those studies with digestive system cancers (HR = 2.05, 95% CI: 1.47–2.62), or with sample size < 70 (HR = 2.70, 95% CI: 1.29–4.11), or with multivariate analysis (HR = 2.04, 95% CI: 1.44–2.64). Moreover, elevated SNHG6 expression was positively associated with tumor invasion depth (OR = 1.76, 95% CI: 1.18–2.63), LNM (OR = 1.60, 95% CI: 1.18–2.17), DM (OR = 1.90, 95% CI: 1.37–2.64) and advanced TNM stage (OR = 1.88, 95% CI: 1.36–2.60) in patients with cancers. CONCLUSIONS: High lncRNA SNHG6 expression was correlated with tumor invasion depth, LNM, DM, and advanced TNM stage, suggesting that SNHG6 may serve as a promising prognostic biomarker of human cancers.