LISBON, Portugal--Although folinic acid and interferon have been shown to heighten the efficacy of 5-fluorouracil (5-FU) in colorectal cancer, the ability of these biochemical modulators to prolong survival is less certain. Now a prospective randomized trial conducted in Germany has revealed that patients with advanced, symptomatic colorectal cancer who are treated with 5-FU and folinic acid live longer and have a better quality of life than do those who receive 5-FU and interferon.
The 142 patients enrolled in this multicenter study underwent chemotherapy with 5-FU, 600 mg/m², given weekly as a 2-hour IV infusion, plus either folinic acid, 200 mg/m² as a bolus, or interferon alfa-2b(Drug information on interferon alfa-2b) (Intron A), 5 million units three times a week.
In his presentation at the congress of the European Society of Medical Oncology, Prof. Dr. med. Ernst D. Kreuser, of University Medical Center Benjamin Franklin, Berlin, said that although response rates did not differ significantly between the two treatment arms, patients in the folinic acid group showed a significantly longer median survival (308 days) than did their interferon-treated counterparts (189 days). "Toxicity of 5-FU was very low, thanks to the 2-hour infusion, with 5% to 10% of patients experiencing gastrointestinal toxicity," Dr. Kreuser noted. "However, flu-like symptoms occurred in 60% of patients treated with interferon."
The German investigators used the new quality of life instrument from the EORTC, QLQ-C 30, along with a supplementary module featuring questions specific for colon cancer, to assess physical, role, cognitive, emotional, and social functioning; pain, fatigue, nausea and vomiting; and global health and global quality of life.
Patients treated with interferon reported progressive increases in somatic symptoms and a significantly worse quality of life than did subjects in the folinic acid group. "Toxicity data do not precisely reflect quality of life," Dr. Kreuser pointed out.
In a multivariate analysis, increased alkaline phosphatase levels and situation of the tumor in the colon compared to the rectum emerged as the only significant harbingers of a poor prognosis in this study. "These two prognostic factors should be applied in future clinical trials," he said.