High-dose folinic acid and 5-fluorouracil bolus and continuous infusion in advanced colorectal cancer: poor response rate in unselected patients.

We have conducted a retrospective study of high-dose folinic acid and 5-fluorouracil in 96 patients with advanced colorectal cancer. Patients received 200 mg m-2 (maximum 300-350 mg) folinic acid by infusion over 2 h followed by an i.v. bolus of 5-fluorouracil 400 mg m-2 then an infusion of 5-fluorouracil 600 mg m-2 over 22 h. This was repeated over the next 24 h. The schedule was given every 2 weeks for four cycles; thereafter patients with objective response continued to a maximum of eight cycles. The overall response rate was 10.6% in 85 evaluable patients. The median duration of response was 11 months. The median survival was 6 months. Toxicity was low, only one patient experiencing toxicity greater than WHO grade II (grade IV platelet toxicity). Diarrhoea, nausea, vomiting and mucositis also occurred but were mild and infrequent. Our low response rate may be related to factors such as patient characteristics or duration of treatment.