Inducible cyclooxygenase (COX-2) in glioblastoma--clinical and immunohistochemical (COX-2-VEGF) correlations.

Cyclooxygenase-2 (COX-2) is the inducible form of the enzyme responsible for the first step in the prostaglandin synthesis. COX-2 upregulation is demonstrated in different tumors. COX-2 products may modulate tumoral growth, apoptosis, metastasis, multidrug resistance and angiogenesis. Moreover, the antitumoral effect of the COX inhibitors has been documented. We studied the immunohistochemical expression and the prognostic value of COX-2 on 43 surgical specimens of glioblastoma-affected patients. Furthermore, we evaluated the correlation between the immunohistochemical expression of COX-2 and vascular endothelial growth factor (VEGF). Of the glioblastomas, 63% resulted as COX-2-positive. Median survival of the patients with COX-2-positive lesions was 10 months; median survival of the patients with COX-2 negative glioblastoma was 21 months (NS). All 4 patients who survived longer than 24 months had COX-2 negative lesions (p = 0.017). Concordance between COX-2 and VEGF was documented in 60% of the cases. Our findings show that glioblastoma can immunohistochemically express COX-2 and that its expression is unrelated with VEGF and significantly less frequent in the long survivors. Nevertheless, the absence of statistical correlation with survival time advises further studies on larger series to ascertain the concrete prognostic value of COX-2 in glioblastoma.