What is the Impact of CSN5 on the Prognosis of Digestive System Cancers: A Systematic Review and Meta-Analysis

Background: Despite the understanding of COP9 signalosome subunit 5 (CSN5) in tumor genesis, there is no conclusive evidence on CSN5 value to predict digestive system tumor patients' survival and prognosis. The article was performed to evaluate the impact of CSN5 expression levels on survival consequence and clinicopathological parameters of digestive system neoplasm patients. Methods: A comprehensive search was conducted through four databases. We utilized Hazard Ratio (HR) with a 95% confidence interval (CI) to evaluate the prognostic value of CSN5 in overall survival (OS) and recurrence free survival (RFS). We estimated the connection between CSN5 and clinicopathological parameters based on Odds Ratio (OR) with a corresponding 95% CI. Results: The meta-analysis contained 22 studies, involving 2,193 patients diagnosed with digestive system tumor. High CSN5 expression level was indicated to predict poorer OS (HR = 2.28, 95% CI: 1.71–3.03; p < 0.00001). Additionally, high CSN5 was correlated with worse invasion depth (OR = 0.49, 95% CI: 0.25-0.96, p = 0.04), positive lymphatic metastasis (OR = 0.28, 95% CI: 0.16-0.47, p = 0.00001), positive distant metastasis (OR = 0.32, 95% CI: 0.13-0.76, p = 0.01) and poorer differentiation degree (OR = 0.34, 95% CI: 0.19-0.60, p = 0.0003). However, we could not find a correlation between CSN5 expression and age, gender, tumor stage, tumor size or vascular invasion. Furthermore, no significant publication bias was detected. Conclusion: This meta-analysis demonstrated that the overexpression of CSN5 level could foresee poorer OS in digestive system cancer patients. Additionally, CSN5 level was related to tumor invasion depth, lymphatic metastasis, distant metastasis and differentiation degree.