ADJUVANT TREATMENT OF PRIMARY MALIGNANT-MELANOMA WITH NATURAL INTERFERON-BETA - SIGNIFICANT SURVIVAL ADVANTAGE IN 96 TREATED PATIENTS COMPARED WITH 288 UNTREATED CONTROLS

In the dermatological department of Dortmund's Municipal Medical Centr e, between May 1986 and April 1991 a total of 105 patients with primar y malignant melanoma (stage I) underwent adjuvant treatment with 5 mil lion IU natural interferon beta as a 30-min i.v. infusion three times weekly for 6 months. During follow-up the patients were examined at sh ort intervals and all recurrences and disease-related cases of death w ere documented up to September 1992. We evaluated the outcome of patie nts treated with interferon beta (n=96 with valid notes of tumour thic kness) compared with untreated historical controls (n=288) matched for tumour thickness, localization, and sex, taken from the Central Malig nant Melanoma Registry (CMMR) of the German Dermatological Society. Th erefore, the main prognostic factors were identical between cases and controls. A computerized randomization was used to fit three control p atients to each treated patient. Survival rate and recurrence-free sur vival were estimated in both groups for a period of 5 years. During th e follow-up 3 patients died in the interferon beta group and the 5-yea r survival rate was 95%, as against 89% in the control group (P<0.05 f or difference between survival curves). Recurrence-free survival curve s were also more favourable for interferon-treated patients than for t he control group (P=0.06). A detailed analysis of high-risk patients w ith tumour thickness of over 1.5 mm also demonstrated obviously better survival (5 years: 95% vs 77%; P=0.012) and recurrence-free survival rates (5 years: 75% vs 53%; P<0.05). These results indicate that natur al interferon beta as adjuvant treatment in patients with primary mali gnant melanoma may be effective in prolonging the recurrence-free inte rval and improving survival.