[Influence of intratumor administration of OK-432 on the tumor selectivity of 5'-DFUR].

The influence of intratumor administration of OK-432 on the tumor-selective antitumor effect of 5'-DFUR was studied in 49 patients with advanced gastric cancer. The patients were divided into 4 groups that received oral 5'-DFUR, intratumor OK-432, oral 5'-DFUR plus intratumor and intracutaneous OK-432, or no therapy before operation. Using surgical specimens, the PyNPase activity and 5-FU content were measured, and the localization of PyNPase was determined immunohistologically. The results were as follows: 1) 5'-DFUR therapy decreased intratumor PyNPase activity whereas administration of OK-432 increased it. 2) PyNPase activity was higher in cancer tissue than in normal tissue for all groups. 3) The 5-FU content of cancer tissue was higher in patients receiving OK-432 plus 5'-DFUR than in patients receiving 5'-DFUR alone. 4) In the resected tumors, PyNPase was mainly localized in the cancer cells of some patients and in the stromal cells of others. Thus, the localization of PyNPase showed two major patterns.