Background: Less than half of patients with melanoma that has spread to local draining regional lymph nodes (stage III melanoma) live with no disease for 5 years or longer after surgery. We aimed to see whether interferon alpha-2a increased survival prospects in these patients.
Methods: 444 patients from 23 centres in the WHO Melanoma Programme had complete lymphadenectomy for pathologically proven regional nodal spread of melanoma and were randomly assigned to receive either 3 MU subcutaneously of recombinant interferon alpha-2a three times a week for 3 years, or to observation alone after surgery. Patients were stratified by centre, nodes with macroscopic or microscopic melanoma, number of affected nodes, and nodal metastatic spread. Treatment was continued for 3 years or until first sign of relapse.
Findings: 424 patients entered the study. 5-year disease-free survival of those who had surgery plus interferon alpha-2a was 27.5% (95% CI 21.7-33.6); for those who received surgery alone, survival was 28.4% (22.5-34.6) (p=0.50). Neither Kaplan-Meier cumulative survival rates, nor multivariate analysis of survival, showed a difference between those who had surgery and interferon alpha-2a (35%, 95% CI 29-42) and those who had surgery alone (37%, 31-44).
Interpretation: Patients with melanoma that has spread to the local draining regional lymph nodes tolerate well 3 MU of interferon alpha-2a given subcutaneously three times a week for 3 years, but this treatment does not improve either disease-free or overall survival.