Cost-effectiveness of chemoprevention of breast cancer using tamoxifen in a postmenopausal US population.

BACKGROUND: Previous cost-effectiveness analyses of tamoxifen therapy account for breast cancer risk reduction during active treatment but not for its persistent protective effect after active treatment.
METHODS: A detailed, continuous time, mathematical model of breast cancer and healthcare processes was used to simulate a postmenopausal population aged <55 years in a virtual trial comparing tamoxifen treatment with no treatment for lifetime follow-up. Unlike previous work, the current model of tamoxifen therapy is based on a meta-analysis of 4 randomized, placebo-controlled chemoprevention trials with breast cancer risk reduction continuing for 10 years after treatment termination. Cancer incidence and survival data were derived from Surveillance, Epidemiology and End Results statistics. Noncancer disease incidences, quality-adjusted life year (QALY) utility weights, and costs were derived from the literature.
RESULTS: Tamoxifen treatment (vs no treatment) saved 29 QALYs in a population of 1000 postmenopausal women aged <55 years with an additional cost of $333,000 over the population's lifetime (average cost-effectiveness ratio, $11,530 per QALY). Tamoxifen therapy, compared with no treatment, was cost saving when higher risk populations were targeted (5-year risk ≥1.66%). The cost-effectiveness results were sensitive to parameters that characterized menopausal symptoms and adverse side effects of tamoxifen.
CONCLUSIONS: The current results indicated that tamoxifen chemoprophylaxis for postmenopausal women aged <55 years is a cost-effective health policy that reduces breast cancer incidence and improves life expectancy. Focusing on a postmenopausal population aged <55 years minimized the threat of adverse events associated with tamoxifen.