Prognostic significance of cyclooxygenase-2 in osteosarcoma: a meta-analysis

Published studies researching the prognostic significance of cyclooxygenase-2 (COX-2) expression in patients with osteosarcoma are inconclusive and heterogeneous. We conducted a meta-analysis to assess its prognostic value more precisely. The pooled odds ratios (ORs) or hazard ratios (HRs) with corresponding 95 % confidence intervals (CIs) were calculated to evaluate the effects. Fourteen studies with 735 osteosarcoma patients were included to estimate the relationship between COX-2 and metastasis of tumor, clinical stage, and 3-year overall survival. High expressions of COX-2 predicted neoplasm metastasis (OR = 1.891, 95 % CI 1.276-2.803, P = 0.002), advanced clinical stage (OR = 1.801, 95 % CI 1.257-2.581, P = 0.001). In addition, high COX-2 expression tended to be associated with a poor 3-year survival (HR = 1.741, 95 % CI 0.762-3.979, P = 0.188), but the difference was not significant. Therefore, this meta-analysis demonstrated that high COX-2 expression might be an unfavorable prognostic effect in osteosarcoma.