[Significance of 5'-deoxy-5-fluorouridine (5'-DFUR) administration before surgery for advanced gastric and colonic cancers--activity of pyrimidine nucleoside phosphorylase (PyNPase) and serum immunosuppressive acidic protein (IAP)].

We administered preoperatively 5'-deoxy-5-fluorouridine (5'-DFUR) for treatment of advanced gastric and colonic cancers, and measured pyrimidine nucleoside phosphorylase (PyNPase) in the excised tumor sample and serum immunosuppressive acidic protein (serum IAP), which is an index of the immunity of host-bearing cancer, while studying its direct antitumor effect and improved immunity. Patients with 24 advanced gastric cancers and 36 colonic cancers were randomly divided into a preoperatively administered group and a non-administered group. In the preoperatively administered group, 5'-DFUR (1,200 mg/day) was orally administered on preoperative days 7 approximately 14. After collecting samples (about 0.5 g) from adjacent normal tissues with tumor within 30 minutes after extirpation of tumor and freezing those less than -20 degrees C, the PyNPase level was measured as soon as possible. Moreever, serum IAP levels at pre-administration in the administered group and on admission in the non-administered group were measured. Those in the administered group were measured again on the operative day. No decreasing tendency of PyNPase was generally found in cases with gastric colonic cancers, and no significant difference in stage-II was not either. However, a decreasing tendency in tumor activity was found by pre-administration. Moreover, there was significant improvement in the serum IAP level in cases with gastric and colonic cancers by pre-operative administration of 5'-DFUR. This tendency was also found in advanced colonic cancer with Dukes-C by Dukes's classification. In conclusion, it was suggested that the pre-operative administration of 5'-DFUR for treatment of advanced gastric and colonic cancers has a favorable influence for prognosis because the tumor region was retarded by the high PyNPase activity according to the severity of tumors and elevating tendency of the immune response in host.