Background: The small nucleolar RNA host gene 7 (SNHG7) has been suggested as a biomarker of metastatic cancer; however, its reliability is controversial. Therefore, the goal of this study was to conduct a meta-analysis to assess the reliability of SNHG7 as a comprehensive cancer metastasis diagnostic biomarker. Methods: A comprehensive literature search was conducted using PubMed, Cochrane Library, Web of Science, Embase, and China National Knowledge Infrastructure (CNKI) to identify articles which examined the role of SNHG7 in cancers. Random-effects models and fixed-effects models were conducted to estimate the pooled odds ratios (ORs) for the associations of SNHG7 with distant metastases and lymph node metastases. Hierarchical summary receiver operating characteristic (ROC) models were used to estimate the sensitivity and specificity of SNHG7 as a biomarker for cancer metastasis diagnoses. Results: Nineteen studies comprised 1491 patients were included in this meta-analysis. We found that both distant metastasis (OR = 4.19, 95% confidence interval [CI] = 2.93-5.99, I2 = 34%) and lymph node metastasis (OR = 3.07, 95% CI = 1.65-5.68, I2 = 79.03%) were significantly associated with a higher expression of SNHG7. We also showed a pooled sensitivity and specificity of 74% (95% CI = 66-82) and 57% (95% CI = 53-61) for distant metastasis; as well as 72% (95% CI = 63-80) and 54% (95% CI = 46-63) for lymph node metastasis, respectively. Conclusion: Our findings suggest that SNHG7 is a potential diagnostic biomarker for metastasis of cancer; however, its clinical application requires stronger evidence due to the low sensitivity and specificity. Further larger-scale studies from diverse settings and cancer types will be necessary to reveal novel insights into SNHG7 as a biomarker for cancer metastasis diagnoses.
Keywords: SNHG7; biomarker; cancer; distant metastasis; long noncoding RNA; lymph node metastasis.