RESUMEN
PURPOSE: Among the pyrimidine nucleoside phosphorylases (PyNPase), thymidine phosphorylase (dThdPase) exists mainly in human tumor tissues, and is an enzyme which converts 5'-deoxy-5-fluorouridine (5'-DFUR) to 5-fluorouracil. Recently, it was reported that dThdPase was identical to platelet-derived endothelial cell growth factor which was an antiogenetic factor, therefore. We think dThdPase may be a prognostic factor. METHODS: We investigated the possible correlation between PyNPase activities in tumor tissues and prognostic factors of histological findings, and examined influences of preoperative oral 5'-DFUR administration at a dose of 1,200 mg/body for 7 days on PyNPase activities and serum immunosuppressive acidic protein levels in patients with gastric cancer. RESULTS: Higher levels of PyNPase activities were especially observed in patients with v+ (p = 0.0161). PyNPase activities (p = 0.1668) and IAP (p = 0.0830) levels showed a decrease by 5'-DFUR administration. CONCLUSION: This study suggests that we must investigate in detail the possibility of PyNPase being prognostic factor, and 5'-DFUR administration may improve the prognosis of patients with gastric cancer.