ABSTRACT
5-Fluorouracil (5FU) is the most important drug in the treatment or gastrointestinal cancer. 5FU can be administered by bolus or continuous infusion. It seems that continuous infusion is capable of producing responses in patients pretreated with bolus of the same drug. To overcome drug resistance in metastatic colon cancer patients, we have administered (via programmable pump) 5FU by prolonged infusion with doses of 250 mg/m2/die for six weeks with a one week rest period. Twenty-one patients with disease progression following bolus 5FU leucovorin were enrolled. The treatment was well tolerated with mucositis (grade I-II) in five patients and hand-foot syndrome in four; these side effects were managed with brief interruption of the infusion. Four partial responses and six stable disease were obtained. Two patients are alive after 14 months. The data of this study suggest that it is possible to overcome acquired 5FU bolus resistance by use of different schedules of the same drug.