Which 5-fluorouracil regimen? - the great debate

5-Fluorouracil (5-FU) has been available for over 40 years and has been use d in a wide variety of different regimens for the treatment of advanced col orectal cancer, a malignancy with a poor prognosis that is common in indust rialized countries. However, despite numerous clinical trials in which 5-FU has been used alone and in combination with a variety of modulating agents [chiefly leucovorin (LV)], and has been administered by bolus injection an d i.v. infusion, the optimal regimen for the management of advanced colorec tal cancer remains unclear, and there are notable national and internationa l variations in clinical practice. The toxicity of 5-FU also remains an obs tacle to the achievement of overall clinical benefit in many patients. The introduction of novel chemotherapeutic agents may make it necessary to reas sess the place of 5-FU in the treatment of advanced colorectal cancer. This article debates these issues with a review of clinical trials of 5-FU, and concludes that the future lies in the utilization of novel and established agents in combinations that may significantly improve outcomes, rather tha n in continuing experimentation with various schedules of 5-FU and LV. [(C) 1999 Lippincott Williams & Wilkins.].