Neurotoxicity of interferon-alpha in melanoma therapy: results from a randomized controlled trial

Background: The objective of this study was to evaluate the neurologic and quality of life impact of low dose adjuvant interferon (IFN)-alpha immunotherapy in patients with malignant melanoma metastatic to regional lymph nodes after radical surgery. Methods: One hundred and thirteen patients were randomized to receive IFN-alpha, 3 x 10(6) IU three times weekly by subcutaneous injection for 36 months or until melanoma recurrence (IFN group), or to act as controls (CTR group). Seventy-five of these patients (66%) entered the toxicity study and underwent formal neurologic, neuropsychologic, psychologic, and quality of life assessments. Patients were assessed at baseline and after 1, 3, 6, and 12 months of follow-up. For each variable, maximum worsening of symptoms from baseline was considered as a response variable. The differences between the two groups regarding this variable were evaluated by means of the Hodges-Lehmann median unbiased point estimates and their 95% confidence interval. Results: A significant degree of action tremor was found in eight patients in the IFN group and in none of the controls. No differences were found during psychiatric evaluation and for cognitive tests. There was a greater increase in anxiety in the IFN group on both trait and state anxiety. With regard to quality of life the analysis showed a significant worsening of at most one level on only three questionnaire items and on the fatigue scale. Conclusions: Neurologic dysfunction associated with IFN therapy was mild. Psychiatric symptoms and neuropsychologic impairment were not found. Levels of fatigue and anxiety were increased in the IFN group but without a sizable impact on quality of life measures.