Prognostic value of SOX2 in digestive tumors: a meta-analysis

Sex determine region Y-box 2 (SOX2) is involved in tumor onset and progress. However its prognostic value for survival in patients with digestive tumors remains controversial.

Publications related to the prognostic significance of SOX2 in digestive tumors were included up to 1 Oct 2013. We computed the pooled hazard ratio and subgroup stratification analysis for overall survival (OS) by software Stata.

A total of eight studies met the inclusion criteria. The pooled results showed that high SOX2 level was not significantly associated with OS in digestive tumors with significant heterogeneity. We then performed a subgroup analysis according to tumor types and patients’ numbers. SOX2 over-expression was associated with a poor OS in hepatocellular carcinoma (HR, 2.56; 95%CI, 1.77–3.71; P=0.000) with no heterogeneity. While in gastric carcinoma, SOX2 over-expression was not associated with OS (HR, 0.83; 95%CI, 0.23–3.03; P=0.773) with obvious heterogeneity. In addition, the sample size affected the pooled results.

Taken together, our findings suggested that SOX2 expression was associated with a poor prognosis in patients with hepatocellular carcinoma, while not for gastric carcinoma. The prognosis role for SOX2 in digestive tumors might vary from different tumor type and different pathology stage. Further large scale multicenter studies need to confirm these results.