THYMIDINE PHOSPHORYLASE-ACTIVITY IN TUMOR CORRELATES WITH VENOUS INVASION

Thymidine phosphorylase (dThdPase) is identical to platelet-derived en dothelial cell growth factor (PD-ECGF), an angiogenesis factor. We inv estigated the correlation between dThdPase activity in gastric cancer tissue and clinicopathological factors. Thirty-three cancer tissue spe cimens and 23 adjacent normal gastric mucosal specimens were obtained from surgery. Measurement of dThdPase activity was based on the amount of 5-fluorouracil formed from 5 '-deoxy-5-fluorouridine by dThdPase. Mean dThdPase activity in cancer tissue was approximately 3.2 times hi gher than that in normal tissue, Cancerous tissues with venous invasio n had about twice the dThdPase activity as cancerous tissues without v enous invasion. Other clinicopathological features were not related to dThdPase activity. A correlation between dThdPase activity and immuno suppressive acidic protein level was observed (r=0.532, P=0.005). dThd Pase activity in gastric cancer cells was found to be correlated with venous invasion, supporting previous findings that it plays a role in tumor angiogenesis.