5-FLUOROURACIL-INTERFERON-ALPHA(2B) ADJUVANT TREATMENT OF DUKES-C COLORECTAL-CANCER

PURPOSE: To determine whether interferon-alpha(2b) can improve results of 5-fluorouracil adjuvant treatment of Dukes C colorectal cancer pat ients, we compared the outcome of patients receiving a fluorouracil-in terferon combination to that of historic controls treated with fluorou racil alone. METHODS: Fifty-seven Dukes C colorectal cancer patients w ere given 5-fluorouracil-interferon-alpha(2b) adjuvant treatment from October 1986 to September 1990. The results were compared with those o btained in 51 consecutive patients treated at the same institutions wi th 5-fluorouracil (5-FU) alone (used at the same doses and schedule) b etween 1983 and 1986. The main prognostic variables were similar in th e two groups. RESULTS: No life-threatening toxicity occurred in either group. The addition of interferon (IFN) slightly impaired tolerance t o the treatment; however, the dose of IFN had to be reduced only in fi ve patients and discontinued in one patient. Grade 3 and 4 myelotoxici ty was rare and not substantially different in the two groups. Interfe ron-related side effects (fever, flu-like syndrome, malaise, etc.) wer e frequent, but, in general, mild or moderate. At the time of this ana lysis (July 1992), median followup was 49 (range, 20-70) months in the group of patients treated with 5-FU + IFN, and 86 (range, 68-103) mon ths in the group receiving 5-FU alone. There were 17 recurrences and 1 5 cancer-related deaths among patients receiving combined treatment, a nd 27 deaths in the group treated with 5-FU alone. Both five-year rela pse-free survival (65 percent vs. 47 percent; P = 0.043) and cause-spe cific survival (64 percent vs. 46 percent; P = 0.038) were significant ly better in the patients receiving combined treatment. After correcti on for the influence of prognostic pretreatment variables, 5-FU + IFN again afforded a significant advantage in terms of both relapse-free ( P < 0.01) and overall survival (P < 0.001). CONCLUSION: 5-FU-IFN-alpha (2b) treatment seems to improve the prognosis in Dukes C colorectal ca ncer patients.