[5-FU concentration in blood and tissue of patients with renal cell carcinoma after administration of UFT].

UFT (3 capsules; 300mg FT) was administered to five of 10 patients with renal cell carcinoma, and concentrations of FT, 5-FU and uracil in the serum and tissues (normal renal tissues, renal tumor tissues and liver) were determined 5.2 hours on average, after administration. The levels were also compared with these in the five patients administered 300 mg of FT. There was no difference in FT concentration between the serum and the tissues in the group administered UFT, but the concentration of 5-FU in tumor tissues was significantly higher (25.6 times) than that in the serum. The level was also higher (3.2 times) than that in normal renal tissues. There was a positive correlation between the concentration of 5-FU in the tissues and the concentration of uracil in the tissues. Although there was no difference in the concentration of FT between serum and tissues in patients administered UFT or FT, the concentration of 5-FU in patients administered UFT was definitely higher than that in patients administered FT; the concentration of 5-FU in the tumor tissues of patients given UFT was 3.9 times higher than in those given FT. Thus, UFT induced a concentration of 5-FU in tumor tissues that was maintained at a high level, suggesting that an excellent antitumor effect on renal cell carcinoma can be expected with UFT.