Treatment of advanced-stage colorectal adenocarcinoma with fluorouracil and high-dose leucovorin calcium: a pilot study.

Thirty-one evaluable patients with measurable advanced colorectal carcinoma were entered into a pilot study that used weekly fluorouracil (5-FU) at the dose of 600 mg/m2 by bolus infusion administered midway during a two-hour leucovorin calcium infusion of 500 mg/m2. This regimen was repeated weekly for six doses. Twenty-seven of these patients (87%) were considered to be refractory to prior 5-FU therapy and four (13%) were previously untreated. All 31 patients successfully completed at least one 6-week cycle of this regimen with acceptable toxicity. The combined complete (CR) and partial response (PR) rate was 45% with another 25% of patients remaining stable. The 95% confidence levels for the responding patients are 27.6% and 62.7%, respectively. The remaining 30% of the patients had all received prior 5-FU therapy and progressed. All of the responding patients and 80% of the patients with stable disease received two or more cycles of this regimen after a 3- to 4-week interval off therapy. The median time to disease progression was 16.1 months for responding patients and 6.7 months for those patients with stable disease. The median survival for the responders was 20.6 months and for those with stable disease 9.8 months. The median survival for the nonresponding patients was 3.9 months. Toxicity included diarrhea in 70% of patients, skin rash (erythema) in 10%, stomatitis in 15%, nausea and vomiting in 25%, and myelosuppression in 10%. This study confirms and extends previous observations that demonstrate the improved efficacy of 5-FU when used with high-dose leucovorin in advanced colorectal carcinoma.