Thymidine phosphorylase/platelet-derived endothelial cell growth factor expression associated with hepatic metastasis in gastric carcinoma

It is known that angiogenesis plays an important role in the growth and metastasis of solid tumours. Several angiogenic factors have been identified and platelet-derived endothelial cell growth factor (PD-ECGF) is thought to be one such factor. Recently, it was reported that thymidine phosphorylase (dThdPase) is identical to PD-ECGF. Using immunohistochemical staining with an anti-dThdPase antibody, we investigated the correlation between dThdPase expression and the microvessel density in 120 gastric carcinomas. The microvessel density, determined by immunostaining for factor VIII-related antigen, was significantly higher in dThdPase-positive tumours than in dThdPase-negative tumours. There was a significant correlation between dThdPase expression and the increment of microvessel density. Moreover, regarding distant organ metastasis, the frequency of hepatic metastasis was significantly higher (P<0.01) in patients with dThdPase-positive rumours than in those with dThdPase-negative tumours. In summary, it was suggested that dThdPase expression is closely associated with the promotion of angiogenesis and hepatic metastasis in gastric carcinoma.