Cyclooxygenase-2 and vascular endothelial growth factor (VEGF) expression in colorectal polyps / 대한내과학회지

ABSTRACT

BACKGROUND: Recent studies showed that non-steroidal antiinflammatory drug may reduce the risk of colorectal cancers. So its potential target, cyclooxygenase (COX)-2 in colorectal cancers has been widely investigated. However, the rate and patterns of COX-2 expression in colorectal polyps have been quite variable among study groups. Furthermore, its role has not been established. The study aim is to investigate the expressions of COX-2 and vascular endothelial growth factor (VEGF) and to evaluate the role of COX-2 in colorectal polyps. METHODS: Fifty-seven colorectal polyps from endoscopic polypectomy or surgical resection were enrolled. Polyps were as follows; 9 were hyperplastic polyps, 14 mild, 26 moderate dysplasia, 8 high grade adenomas (5 severe dysplasia, a carcinoma in situ, and two intramucosal carcinomas). They were stained for COX-2 and VEGF by immunohistochemistry. The intensity of staining according to histologic grades and size of polyp was semi-quantitatively assessed. RESULTS: COX-2 was expressed in 18 cases (31.8%) by dysplastic epithelium and 29 cases (50.9%) by interstitial cells. Epithelial COX-2 expressions were significantly related to histologic grades and size, and begun at moderate dysplasia actually. Interstitial COX-2 was little related to histologic grades and size. VEGF was expressed in 35 cases (61.4%). There was close relationship between epithelial COX-2 and VEGF expressions. CONCLUSION: COX-2 is expressed both in dysplastic epithelium and interstitial cells of colorectal polyps. Our results suggest that epithelial COX-2 expression may be playing a role in tumorigenesis of colorectal polyp, possibly involved in angiogenesis with VEGF.