Identifying cost-effective treatment with raloxifene in postmenopausal women using risk algorithms for fractures and invasive breast cancer.

INTRODUCTION: The National Osteoporosis Foundation (NOF) recommends considering treatment in women with a 20% or higher 10-year probability of a major fracture. However, raloxifene reduces both the risk of vertebral fractures and invasive breast cancer so that raloxifene treatment may be clinically appropriate and cost-effective in women who do not meet a 20% threshold risk. The aim of this study was to identify cost-effective scenarios of raloxifene treatment compared to no treatment in younger postmenopausal women at increased risk of invasive breast cancer and fracture risks below 20%. METHOD: A micro-simulation model populated with data specific to American Caucasian women was used to quantify the costs and benefits of 5-year raloxifene treatment. The population evaluated was selected based on 10-year major fracture probability as estimated with FRAX® being below 20% and 5-year invasive breast cancer risk as estimated with the Gail risk model ranging from 1% to 5%. RESULTS: The cost per QALY gained ranged from US $22,000 in women age 55 with 5% invasive breast cancer risk and 15-19.9% fracture probability, to $110,000 in women age 55 with 1% invasive breast cancer risk and 5-9.9% fracture probability. Raloxifene was progressively cost-effective with increasing fracture risk and invasive breast cancer risk for a given age cohort. At lower fracture risk in combination with lower invasive breast cancer risk or when no preventive raloxifene effect on invasive breast cancer was assumed, the cost-effectiveness of raloxifene worsened markedly and was not cost-effective given a willingness-to-pay of US $50,000. At fracture risk of 15-19.9% raloxifene was cost-effective also in women at lower invasive breast cancer risk. CONCLUSIONS: Raloxifene is potentially cost-effective in cohorts of young postmenopausal women, who do not meet the suggested NOF 10-year fracture risk threshold. The cost-effectiveness is contingent on their 5-year invasive breast cancer risk. The result highlights the importance of considering a woman's full risk profile when considering anti-osteoporosis treatment.