Significance of COX-2 Expressions in Carcinoma of the Gallbladder

ABSTRACT

PURPOSE: Enhanced COX-2 expression has been observed in various solid tumors. A gallbladder carcinoma often evolves from a gallbladder adenoma, or chronic cholecystitis with cholelithiasis. It has been postulated that COX-2 might have an important role in the carcinogenesis of a gallbladder carcinoma. The purpose of this study was to identify the role of COX-2 in the carcinogenesis of gallbladder carcinomas, and find the relationships between COX-2 expression and the prognostic factors, including the survival of patients. METHODS: Three tissue microarray blocks were made from 23 cases of cholecystitis, 40 cases of a gallbladder adenoma and 67 cases of a gallbladder carcinoma. Immunohistochemical stains for COX-2 were performed, and the staining intensity and patterns evaluated. The relationships between COX-2 expression and the histopathological parameters of the gallbladder carcinoma were analyzed, and a postoperative survival analysis also performed. RESULTS: The rates of COX-2 expression were 52.2, 37.5 and 47.8% in the gallbladder carcinomas, gallbladder adenomas and chronic cholecystitis, respectively, and showed no significant differences (p=0.334). The overall expression rate was 46.9%. In the gallbladder carcinomas, COX-2 expression had no significant relationships with the tumor size (p=0.197), histological grade (p=0.859), depth of invasion (p=0.978) and lymph node metastasis (p=0.730). COX-2 expression in the followed-up patients with gallbladder carcinomas showed no relationships with the survival of the patients (p=0.087). CONCLUSION: COX-2 expression may play a role in the carcinogenesis of gallbladder carcinomas, but does not act as a prognostic indicator of a gallbladder carcinoma.