5-FU, FT-207 and uracil concentrations in the serum and tissues of patients with cervical cancer after UFT oral administration

The concentrations of 5-FU, FT-207 and uracil were estimated in blood serum, cancer tissue and normal tissue of patients with uterine cervical cancer. A daily dose of 600 mg of UFT was administrated for 7 days to cervical cancer patients, and they received radical hysterectomy and pelvic lymphadenectomy. After single administration of UFT, the serum concentration of 5-FU was highest at 60 minutes (0.094 micrograms/ml) and became reduced with time. On the other hand, when UFT was administered for 7 consecutive days, the serum concentration of 5-FU was found to reach a plateau between 60 minutes (0.215 micrograms/ml) and 120 minutes (0.222 micrograms/ml) with gradual decline thereafter. Significantly higher levels of 5-FU were achieved at 60 min. and 120 min. and apparent accumulation of 5-FU in serum was observed following continuous administration of UFT. Similar results were observed regarding the change of serum concentration of uracil, while FT-207 was observed to remain in serum for a longer time than 5-FU. In the uterine cervix, the concentration of 5-FU cancer tissue was 0.087 micrograms/ml, approximately 3 times that of normal tissue, and approximately 5.1 times that of the preoperative serum concentration of 5-FU, indicating a tendency to accumulate in cancer tissue. Although a higher concentration of 5-FU was detected in pelvic lymph nodes and ovaries, no significant differences were recognized between metastatic nodes and metastasis-free nodes.