A REVIEW OF GERCOD TRIALS OF BIMONTHLY LEUCOVORIN PLUS 5-FLUOROURACIL48-H CONTINUOUS-INFUSION IN ADVANCED COLORECTAL-CANCER - EVOLUTION OFA REGIMEN

The addition of leucovorin (LV) to 5-fluorouracil (5-FU) in advanced c olorectal cancer has shown improved tumour response rates in many tria ls, but the optimal LV/5-FU regimen has yet to be determined. Seven st udies carried out over the last 12 years to evaluate the safety and ef ficacy of various LV/5-FU regimens are reviewed. The initial bimonthly high-dose LV/5-FU regimen consisted of high-dose LV as a 2-h infusion followed by 5-FU as an intravenous (i.v.) bolus plus a 22-h continuou s infusion (CI), repeated for two consecutive days every 2 weeks. A ra ndomised comparison of this bimonthly high-dose LV/5-FU regimen and th e NCCTG-Mayo Clinic regimen (LV [20mg/m(2)/day] followed by 5-FU bolus [425 mg/m(2)/day] daily x 5, every 4 weeks) showed that the bimonthly high-dose LV/5-FU regimen was superior to the NCCTG-Mayo Clinic regim en in response rate and progression-free survival, but showed no diffe rence in overall survival. In addition, toxicity was less with the bim onthly high-dose LV/5-FU regimen. These promising results led to a pha se II trial of a simplified bimonthly high-dose LV/5-FU regimen consis ting of LV (500 mg/m(2)/day) and a 48-h CI of 5-FU (1.5-2 g/m(2)/day) which has been administered alone or in combination. In summary, GERCO D-sponsored studies have further demonstrated that higher doses of bot h LV and 5-FU given as a CI can improve response rates still more with acceptable toxicity. Further studies are focused on the effectiveness of combination with oxaliplatin or CPT-11 in metastatic disease and t he use of high-dose LV/5-FU regimens for colorectal cancer in the adju vant setting. (C) 1997 Elsevier Science Ltd. All rights reserved.