Association of osteopontin expression with the prognosis of glioma patient: a meta-analysis.

So far, several studies on the association between osteopontin (OPN) expression and glioma have been performed, but the conclusion still was not clear. The aim of the present meta-analysis was to determine the relationship between OPN expression and prognosis of patients with glioma. The electronic database was searched for articles on the association between OPN expression and glioma until 31 January 2014. Odds ratios (OR) and the relative risks with 95 % CI were utilized to analyze the qualitative data in retrospective studies and prospective studies, respectively. The standardized mean difference and the corresponding 95 % CI were used for analyzing the studies with quantitative data. Heterogeneity of all included studies was assessed using Cochrane's Q test and I (2) measurement. The publication bias was examined by the Egger test. Sixteen cohort studies (854 patients) on OPN expression and gliomas prognosis were included in the present meta-analysis. It was found that OPN expression was significantly higher in patients with high-grade glioma than in patients with low-grade glioma (χ (2) = 8.38, I (2)  = 16.6 %, P = 0.300), and the expression of OPN increased with glioma grade. The combined data showed the correlation between high OPN expression and tumor reoccurrence (OR = 18.61, 95 % CI = 6.34-54.67, P = 0.405). In addition, the results of the pooled analysis indicated that OPN expression was significantly related to overall survival (HR = 1.83; 95 % CI = 1.36-2.46). In conclusion, OPN may be a biomarker for predicting the prognosis of gliomas.