Cost effectiveness of adjuvant interferon in node-positive melanoma.

PURPOSE To assess the benefits of adjuvant high-dose interferon alfa (HDI) treatment for patients with high-risk melanoma. METHODS We designed a decision-analytic probabilistic Markov model to simulate the natural history of patients with stage IIIA, IIIB, and IIIC melanoma and evaluate the outcomes with and without HDI treatment. Outcomes were in quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). Probability estimates and costs were derived from primary patient level data, while the efficacy of HDI and associated utilities were determined from published reports. The base-case analysis was a cohort of 50-year-old patients. RESULTS HDI increased the median life expectancy in patients with stage III melanoma from 3.75 years in the observation cohort to 4.42 years in the HDI cohort. The difference in QALYs ranged from 0.31 years for stage IIIA patients to 0.60 years for stage IIIC patients treated with HDI. HDI was cost effective in patients with stage IIIB and IIIC melanoma, with ICERs of $95,304 and $76,068 per QALY gained, respectively. Using a threshold of $100,000 per QALY gained, HDI was cost effective for all stage III patients younger than 52 years. HDI was not cost effective for patients with stage IIIA disease and for subsets of patients older than 63 years with stage IIIB disease. CONCLUSION Our model demonstrates that the probability of HDI being cost effective varies substantially by melanoma substage. HDI showed the greatest benefit in terms of QALYs and was most cost effective in patients younger than 60 years with stage IIIC disease.