Efficacy of low-dose interferon {alpha}2a 18 versus 60 months of treatment in patients with primary melanoma of >= 1.5 mm tumor thickness: results of a randomized phase III DeCOG trial.

PURPOSE Low-dose (LD) interferon (IFN) alfa (LDI) has demonstrated a consistent disease-free survival benefit for patients with clinically lymph node-negative melanoma in clinical trials. However, the optimal duration of treatment is still under discussion, and no previous trial has evaluated this question specifically. A prolongation of LDI from 18 months to 60 months might be of clinical benefit for patients with intermediate or high-risk melanoma. PATIENTS AND METHODS Eight hundred fifty patients with resected cutaneous melanoma of at least 1.5 mm tumor thickness were included in this prospective randomized, multicenter trial in Germany and Austria. Patients had to be clinically lymph node-negative, and sentinel node biopsy (SLNB) was performed in a majority of cases. They were randomly assigned to receive 3 MU IFNalpha2a three times a week subcutaneously for either 18 months (arm A) or 60 months (arm B). Results Of 850 randomly assigned patients, 840 were eligible for evaluation after a median follow-up of 4.3 years. Tumor thickness and other relevant prognostic factors were well balanced between both groups. SLNB was performed in 635 patients (75.6%), with a positivity rate of 18.0% in arm A and 17.5% in arm B. Neither relapse-free survival (arm A, 75.6% v arm B, 72.6%; P = .72; hazard ratio, 1.05; 95% CI, 0.80 to 1.39) nor distant-metastasis-free survival (81.9% v 79.7%; P = .56; HR, 1.10; 95% CI, 0.80 to 1.52) or overall survival (85.9% v 84.9%; P = .86; HR, 1.03; 95% CI, 0.71 to 1.50) showed significant differences. CONCLUSION A prolongation of conventional LDI therapy from 18 to 60 months showed no clinical benefit in patients with intermediate and high-risk primary melanoma.