ABSTRACT
BACKGROUND: Owing to the limited efficacy of therapy on melanoma at the stage of distant metastases, a well-tolerated adjuvant therapy is needed for patients with high-risk primary melanoma. Our hypothesis was that an adjuvant treatment with low doses of interferon alpha could be effective in patients with localised melanoma. METHODS: After resection of a primary cutaneous melanoma thicker than 1.5 mm, patients without clinically detectable node metastases were randomly assigned to receive either 3x10(6) IU interferon alpha-2a, three-times weekly for 18 months, or no treatment. The primary endpoint was the relapse-free interval. FINDINGS: 499 patients were enrolled, of whom 489 were eligible. When used as part of a sequential procedure, interferon alpha-2a was of significant benefit for relapse-free interval (p=0.038). A long-term analysis, after a median follow-up of 5 years, showed a significant extension of relapse-free interval (p=0.035) and a clear trend towards an increase in overall survival (p=0.059) in interferon alpha-2a-treated patients compared with controls. There were 100 relapses and 59 deaths among the 244 interferon alpha-2a-treated patients compared with 119 relapses and 76 deaths among the 245 controls. The estimated 3-year-relapse rates were 32% in the interferon alpha-2a group and 44% in controls; the 3-year death rates were 15% and 21%, respectively. Only 10% of patients experienced WHO grade 3 or 4 adverse events. Treatment was compatible with normal daily life. INTERPRETATION: Adjuvant therapy of high-risk melanoma with low doses of interferon alpha-2a for 18 months is safe and is beneficial when started before clinically detectable node metastases develop.
