Cyclo-oxygenase-2 overexpression is a feature of early and well-differentiated hepatocellular carcinoma with a favourable prognosis

Aims: To determine the prognostic relevance of cyclo-oxygenase-2 (COX-2) expression in hepatocellular carcinoma (HCC) and its relationship to important clinicopathological parameters. Methods: A series of 196 patients with HCCs treated either by surgical resection (n = 106) or liver transplantation (n = 90) was investigated. Immunohistochemically confirmed COX-2 expression was correlated with a series of clinicopathologically relevant parameters as well as proliferative activity and apoptosis. Results: Overexpression of COX-2 correlated statistically with high histological tumour differentiation (p < 0.001) and early TNM stage (p = 0.003). COX-2 overexpression was associated with lower apoptotic rates (p = 0.001), whereas proliferation activity did not differ significantly. In addition, COX-2 overexpression showed a significant correlation with favourable overall survival (p < 0.001). In multivariate survival analysis, COX-2 expression qualified as an independent prognostic parameter (p = 0.030). Conclusions: Overexpression of COX-2 in HCC indicates early-stage cancer with less aggressive tumour behaviour and constitutes an independent prognostic factor.