Effective biomodulation by leucovorin of high-dose infusion fluorouracil given as a weekly 24-hour infusion: results of a randomized trial in patients with advanced colorectal cancer.

PURPOSETo determine whether high-dose infusional fluorouracil (FU) is effectively modulated by leucovorin (LV), interferon (IFN) alpha-2b, or both when given to patients with metastatic colorectal cancer.PATIENTS AND METHODSPatients (n = 236) with progressive, measurable disease were randomized to three groups and received FU 2,600 mg/m2 as a 24-hour continuous infusion (CI) weekly for 6 weeks with 2 weeks rest (FU24h) and LV 500 mg/m2 as a 2-hour infusion before FU or IFN 3 x 10(6) U subcutaneously 3 times weekly or both. Treatment continued until progressive disease or unacceptable toxicity was observed. Pairs of treatment arms were analyzed sequentially to detect equivalence or a 25% difference in response rates.RESULTSThe rate of objective remission in patients who received FU24h/LV (44%; 40 of 91) was significantly higher than in patients who received FU24h/IFN (18%; 16 of 90; P < .05). The response rates of patients who received FU24h/LV versus FU24h/LV/IFN (27%; 13 of 49) were statistically equival...