Correlation between expression of platelet-derived endothelial cell growth factor (thymidine phosphorylase) and microvessel density in early-stage human colon carcinomas.

Platelet-derived endothelial cell growth factor may play a role in tumor development through its angiogenic action. To clarify the relationship between expression of platelet-derived endothelial cell growth factor and microvessel density in the development of human colon carcinoma, we examined 80 early-stage colon carcinomas using microscopy and immunohistochemistry. Localization of platelet-derived endothelial cell growth factor was assessed by immunocytochemistry, while microvessel count was evaluated by either HE staining or Factor VIII immunostaining. Among the examined carcinomas, 35 were classified as m carcinomas including carcinoma in situ, whereas 45 were sm carcinomas. Fifteen (42.9%) of the 35 m and 30 (66.7%) of the 45 sm carcinomas demonstrated high vascular density, whereas 20 (57.1%) m and 15 (33.3%) sm carcinomas showed moderate or low vascular density. Vascular density was higher in sm carcinomas than in m carcinomas and there was a significant correlation between depth of invasion and vascular density. Of the 45 highly vascularized carcinomas, 44 expressed platelet-derived endothelial cell growth factor. There was a statistically significant correlation between the frequency of platelet-derived endothelial cell growth factor expression and microvessel density (P = 0.012). These data demonstrate that microvessel density may be associated with the depth of cancer invasion and that platelet-derived endothelial cell growth factor may play an important role in the early stage of colon cancer development through angiogenesis.