Yes-Associated Protein 1 as a Novel Prognostic Biomarker for Gastrointestinal Cancer: A Meta-Analysis

BACKGROUND: Yes-associated protein 1 (YAP1) is an effector of Hippo pathway, which plays a significant role in cell proliferation and tumor progression. The relationship between YAP1 and gastrointestinal cancer has been explored in many previous studies. We conducted a meta-analysis to explore the prognostic effect of YAP1 in patients with gastrointestinal cancer. METHODS: A systematic search was performed through the PubMed, Web of Science, Embase, and Cochrane library databases to collect eligible studies. The pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were used to evaluate the relationship between YAP1 expression and gastrointestinal cancer clinical outcomes. RESULTS: A total of 2941 patients from 18 studies were enrolled. The results showed that elevated YAP1 expression predicted a poor prognosis in gastrointestinal cancer (HR = 1.56; 95% CI: 1.29-1.89; P < 0.001). Subgroup analyses indicated significant association between YAP1 overexpression and shorter OS of patients with esophageal squamous cell carcinoma (HR = 1.85; 95% CI: 1.25-2.73; P = 0.002), gastric cancer (HR = 1.41,95% CI: 1.02-1.95; P = 0.037), and colorectal cancer (pooled HR = 1.75; 95% CI: 1.42-2.15; P < 0.001). However, YAP1 expression did not affect DFS of patients with gastrointestinal cancer (pooled HR = 1.33; 95% CI: 0.95-1.88; P = 0.101). CONCLUSION: Elevated YAP1 expression in patients with gastrointestinal cancer might be related to shorter OS. YAP1 protein could serve as a potential predictor of poor prognosis in gastrointestinal cancer.