A phase I study. UFT/leucovorin combined with paclitaxel for anthracycline-pretreated advanced breast cancer.

Taxanes are the most active drugs in the treatment of metastatic breast and ovarian cancer. Weekly therapy with paclitaxel produces notable activity, with remarkably low toxicity. Moreover, combination therapy with paclitaxel and fluorouracil (5-FU) exhibits high activity in anthracycline-pretreated breast cancer patients: recent studies report response rates of 54% to 69%. UFT plus oral leucovorin constitutes an orally administered compound that provides activity comparable to that of intravenously administered 5-FU plus leucovorin. An open-label phase I study was initiated to determine the maximum tolerated dose and dose-limiting toxicities of the combination of weekly paclitaxel and UFT plus leucovorin administered to patients with anthracycline-resistant metastatic breast cancer.