Modeling for cost-effective-adjuvant aromatase inhibitor strategies for postmenopausal women with breast cancer.

BACKGROUND: To determine cost-effective (CE) strategies comparing adjuvant upfront aromatase inhibitor (AI) with sequential tamoxifen (TAM) AI in postmenopausal (PM) women with breast cancer (BC). Design: A Markov model was constructed to calculate cumulative costs and quality-adjusted life year (QALY) gains for upfront AI and TAM-AI in a hypothetical cohort of 60-year-old PM women with BC. Costs, utilities and probabilities were derived from the literature. The hazard ratios (HRs) of AI strategies were applied to a baseline cancer recurrence risk (RR) to determine CE strategies at the $50,000/QALY gain threshold. A direct payer perspective is utilized, and costs and benefits were discounted at 3%. RESULTS: Two-way sensitivity analyses are presented to determine CE strategies across a wide range of HRs and in different clinical scenarios including varying RRs (low, average, high and very high). TAM-AI is the preferred CE strategy at low and average RR, while upfront AI is CE at very high RR. The CE strategy in patients with high RR was dependent on the scenario examined. CONCLUSIONS: This model may help health care providers select CE-adjuvant AI strategies in PM women with BC, until further direct evidence is available from randomized clinical trials.