[Studies on 5-FU concentration in serum and bladder tumor tissue after oral administration of UFT]

The concentration of 1-(2-tetrahydrofuryl)-5-fluorouracil (FT), 5-fluorouracil (5-FU) and uracil in blood, the bladder tumor tissue and the bladder mucosa after oral administration of 600 mg per day of UFT for 7 consecutive days was examined in 10 cases of bladder tumors. The concentration of FT and uracil in the tumor tissue did not significantly increase as compared with that in the blood and the bladder mucosa. However, the concentration of 5-FU in the tumor tissue remarkably increased and was 10.7 and 4 times as much as that in the blood and the bladder mucosa, respectively. These results show that administration of UFT meaningfully increases the 5-FU content in bladder tumors and enhances the antitumor activity.