Treat Now or Treat Later: Comparative Effectiveness of Adjuvant Therapy in Resected Stage IIIA Melanoma.

BACKGROUND: Adjuvant therapy for most sentinel-node-positive (stage IIIA) melanoma may have limited clinical benefit for older patients given the competing risk of non-cancer death. The objective of this study is to model the clinical effect and cost of adjuvant therapy in stage IIIA melanoma across age groups. STUDY DESIGN: A Markov decision analysis model simulated the overall survival of patients with resected stage IIIA melanoma treated with adjuvant therapy vs observation. In the adjuvant approach, patients are modeled to receive adjuvant pembrolizumab (BRAF wild type) or dabrafenib/trametinib (BRAF mutant). In the observation approach, treatment is deferred until recurrence. Transition variables were derived from landmark randomized trials in adjuvant and salvage therapy. The model was analyzed for age groups spanning 40 to 89 years. The primary outcome was the number needed to treat (NNT) to prevent one melanoma-related death at 10 years. Cost per mortality avoided was estimated using Medicare reimbursement rates. RESULTS: Projections for NNT among BRAF wild type patients increased by age from 14.71 (age 40 to 44) to 142.86 (age 85 to 89), with patients in cohorts over the age of 75 having an NNT over 25. The cost per mortality avoided ranged from $2.75 million (M) (age 40 to 44) to $27.57M (age 85 to 89). Corresponding values for BRAF mutant patients were as follows: NNT 18.18 to 333.33; cost per mortality avoided ranged from $2.75M to $54.70M. CONCLUSION: Universal adjuvant therapy for stage IIIA melanoma is costly and provides limited clinical benefit in patients older than 75 years.