SOX2 contributes to invasion and poor prognosis of gastric cancer: A meta-analysis

Background: The sex-determining region Y-box 2 (SOX2) has been identified to be involved in tumor progression and prognosis in patients with gastric cancer (GC). However, its action is paradoxical. Thus, we conducted the first meta-analysis based on eligible studies to evaluate the clinical utility of SOX2 in GC only. Methods: A thorough electronic search was performed to collect eligible studies. The hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were generated from included studies to assess the strength of the association between SOX2 and prognosis and clinicopathological characteristics in GC. Results: A total of 10 studies comprising 1321 patients with GC were identified for the meta-analysis. The pooled results revealed that high SOX2 expression was significantly associated with poor overall survival compared to low SOX2 expression (pooled HR = 1.485; 95% CI: 1.022-2.160; P =.04). The statistical significance between SOX2 expression and overall survival was also established in univariate analysis (pooled HR = 1.606; 95% CI: 1.134-2.274; P <.01), as well as recruitment time exceeding 2010 (pooled HR = 1.873; 95% CI: 1.041-3.371; P =.04), follow-up time more than 5 years (pooled HR = 1.642; 95% CI: 1.066-2.527; P =.02), and cutoff value of more than 5% of cells stained (pooled HR = 1.730; 95% CI: 1.162-2.577; P <.01). Moreover, we verified that positive SOX2 expression was correlated with advanced tumor invasion depth (pooled OR = 0.494; 95% CI: 0.362-0.675; P <.01) and positive vascular invasion (pooled OR = 1.515; 95% CI: 1.078-2.130; P =.02). Conclusion: SOX2 could not only be an independent prognostic marker in GC but might also be a novel target for cancer therapy.