Protracted intravenous infusion of 5-fluorouracil in combination treatments. A review

5-fluorouracil (5-FU) administered by protracted intravenous infusion has been shown to have clinical utility against colorectal cancer and several other advanced tumors. However, additional therapeutic strategies are needed to further improve treatment results. Although the addition of low-dose cisplatin appeared to improve the clinical activity of 5-FU infusion in early phase II studies, subsequent evaluation has failed to substantiate these early reports. In addition, toxicity has been significantly increased. Combinations of cisplatin and other drugs with 5-FU infusion are currently being evaluated. Phase I studies demonstrate that only low doses of concomitant leucovorin are necessary to potentiate 5-FU infusion; phase II studies to evaluate efficacy are underway. Although combinations of 5-FU and biological therapies such as alpha 2a-interferon appear to be very promising, they will require extensive phase II and III testing to define their clinical utility and toxicity.