Aims and background: This study was conducted to investigate the activity and toxicity of 5fluorouracil folinic acid+mitomycin C combined with alpha 2b interferon in advanced colorectal cancer based upon recent studies suggesting a possible biochemical modulation of 5fluorouracil by interferon.
Patients and methods: Between June 1990 and April 1991 25 previously untreated patients with advanced colorectal carcinoma were treated with mitomycin C 10 mg/m2 iv bolus on day 1, 5fluorouracil 375 mg/m2 on days 1 to 4 and folinic acid 200 mg/m2 on days 1 to 4 every 4 weeks, combined with alpha 2b interferon 3 million U day continuously.
Response: Of the 25 patients entered into the study, 20 were evaluable for response as 5 patients withdrew due to toxicity (grade 3-4 thrombocytopenia in 4 cases and fatigue in 1). No complete response was recorded, 6 patients had partial remission (30%; 95% confidence interval, 10% to 50%), 4 experienced no change and 10 showed progressive disease. The toxicity of this regimen was significant, particularly myelosuppression.
Conclusions: This combination showed a significant toxicity and low response rate compared with other 5fluorouracil based regimens in advanced colorectal cancer.