COX-2 expression of ampullary carcinoma: correlation with different histotypes and clinicopathological parameters

Epidemiological studies suggest that regular intake of nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with reduced incidence of gastrointestinal cancer. Several lines of evidence indicate that the antineoplastic effect of NSAIDs is attributable to COX-2 inhibition. The aim of our study was to assess COX-2 expression in a series of primary untreated ampullary carcinomas and its possible correlation with clinicopathological parameters. In the present study, 45 surgical specimens of invasive ampullary carcinomas were histologically classified into pancreaticobiliary, intestinal, and unusual types. COX-2 expression by immunohistochemical method was analyzed. High COX-2 expression was detected in 35 (77.8%) ampullary carcinomas. Among these, 20/21 (95.2%) were classified as intestinal, 9/18 (50%) pancreaticobiliary, and 6/6 (100%) unusual type. A significant statistical difference in terms of COX-2 expression was found between pancreaticobiliary vs intestinal type (P=0.002). Furthermore, a negative significant statistical correlation was found between T factor and COX-2 expression (P=0.047). The different COX-2 expression among histopathological types supports the concept of histogenetical difference of ampullary carcinomas. Furthermore, the high rate of COX-2 expression in the intestinal subtype of ampullary carcinoma may represent the rational for a histotype-tailored therapy targeting COX-2.