[The serum and tissue concentrations of tegafur, 5-fluorouracil and uracil in patients with gastric and colorectal cancers after oral administration of UFT].

Fifteen patients with stomach cancer and colorectal cancer were orally administered 600 mg of UFT before operation and the concentration of tegafur, 5-fluorouracil (5-FU) and uracil in the tissues and serum were measured by chemical assay. The mean 5-FU levels in tumor and lymph node were higher than those in normal tissues and were maintained in tumor for long time. Uracil level in tumor tissue was higher than in normal tissue with or without administration of UFT. Positive correlation between the concentration of uracil and 5-FU in the colorectal tumor with the correlation coefficient of 0.87 (p less than 0.01) was obtained.