Expression of Cyclooxygenase-2 in Urothelial Carcinoma of the Human Urinary Bladder

Park, Min Kyu; Chung, Jae Il; Jung, Soo Jin; Choi, Sung Hyup

Abstract

PURPOSE: Urinary bladder cancer is the most common tumor of all urologic cancers in Korea. Recent studies have supported the important role of cyclooxygenase-2 (COX-2) in various cancers derived from epithelial cells, such as the breast, gastrointestinal tract, prostate, head and neck. This study was performed to evaluate the relationship between cyclooxygenase-2 expression and prognosis in urothelial carcinoma of the human urinary bladder.
MATERIALS AND METHODS
We assessed the clinicopathologic results from 57 bladders of urothelial carcinomas patients who underwent radical cystectomy. To evaluate the expression of COX-2, paraffin sections were assessed with immunohistochemistry using the anti-human COX-2 monoclonal antibody and staining intensity was evaluated. The relationships between COX-2 expressions and stage, grade and lymph node metastasis were statistically analyzed and the association with survival rate was also evaluated.
RESULTS
COX-2 was overexpressed in 12 out of the 57 cases (21%) in urothelial carcinomas of the urinary bladder. COX-2 overexpression rate was gradually increased from stage T1 (7.1%) and T2 (31.2%) to stage T3 (50.0%) (p=0.0177) and was increased in high grade urothelial carcinoma (32.3%) compared with that in low grade urothelial carcinoma (7.7%) (p=0.0235). The survival rate of patients with higher stage and high histologic grade was poorer than that of patients with lower stage and low histologic grade (p<0.05). Whereas 35 (77.8%) out of 45 COX-2 negative cases were alive, only six (50.0%) out of 12 COX-2 positive cases were alive. However, the difference was not statistically significant (p>0.05).
CONCLUSIONS
This study showed that COX-2 overexpression was highly correlated with stage and histologic grade in urothelial carcinomas of the human urinary bladder. These results support the possibility that COX-2 might be an important factor related to the aggressive behavior of urothelial carcinoma of the urinary bladder.