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INTRODUCTION: Aromatase-inhibitors (AIs) are commonly used for treatment of patients with hormone-receptor positive breast carcinoma, and are known to induce bone density loss and increase the risk of fractures. The current standard-of-care screening tool for fracture risk is bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA). The fracture risk assessment tool (FRAX®) may be used in conjunction with BMD to identify additional osteopenic patients at risk of fracture who may benefit from a bone-modifying agent (BMA). The trabecular bone score (TBS), a novel method of measuring bone microarchitecture by DXA, has been shown to be an independent indicator of increased fracture risk. We report how the addition of TBS and FRAX®, respectively, to BMD contribute to identification of elevated fracture risk (EFR) in postmenopausal breast cancer patients treated with AIs. METHODS: 100 patients with early stage hormone-positive breast cancer treated with AIs, no prior BMAs, and with serial DXAs were identified. BMD and TBS were measured from DXA images before and following initiation of AIs, and FRAX® scores were calculated from review of clinical records. EFR was defined as either: BMD ≤-2.5 or BMD between -2.5 and -1 plus either increased risk by FRAX® or degraded microstructure by TBS. RESULTS: At baseline, BMD alone identified 4% of patients with EFR. The addition of FRAX® increased detection to 13%, whereas the combination of BMD, FRAX® and TBS identified 20% of patients with EFR. Following AIs, changes in TBS were independent of changes in BMD. On follow-up DXA, BMD alone detected an additional 1 patient at EFR (1%), whereas BMD+ FRAX® identified 3 additional patients (3%), and BMD+FRAX®+TBS identified 7 additional patients (7%). CONCLUSIONS: The combination of FRAX®, TBS, and BMD maximized the identification of patients with EFR. TBS is a novel assessment that enhances the detection of patients who may benefit from BMAs.
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BACKGROUND: Androgen deprivation therapy (ADT) increases the risk for fractures in patients with prostate cancer. OBJECTIVE: To assess the cost-effectiveness of measuring bone mineral density (BMD) before initiating ADT followed by alendronate therapy in men with localized prostate cancer. DESIGN: Markov state-transition model simulating the progression of prostate cancer and the incidence of hip fracture. DATA SOURCES: Published literature. TARGET POPULATION: A hypothetical cohort of men aged 70 years with locally advanced or high-risk localized prostate cancer starting a 2-year course of ADT after radiation therapy. TIME HORIZON: Lifetime. PERSPECTIVE: Societal. INTERVENTION: No BMD test or alendronate therapy, a BMD test followed by selective alendronate therapy for patients with osteoporosis, or universal alendronate therapy without a BMD test. OUTCOME MEASURES: Incremental cost-effectiveness ratio (ICER), measured by cost per quality-adjusted life-year (QALY) gained. RESULTS OF BASE-CASE ANALYSIS: The ICERs for the strategy of a BMD test and selective alendronate therapy for patients with osteoporosis and universal alendronate therapy without a BMD test were $66,800 per QALY gained and $178,700 per QALY gained, respectively. RESULTS OF SENSITIVITY ANALYSES: The ICER for universal alendronate therapy without a BMD test decreased to $100,000 per QALY gained, assuming older age, a history of fractures, lower mean BMD before ADT, or a lower cost of alendronate. LIMITATIONS: No evidence shows that alendronate reduces actual fracture rates in patients with prostate cancer who receive ADT. The model predicted fracture rates by using data on the surrogate BMD end point. CONCLUSION: In patients starting adjuvant ADT for locally advanced or high-risk localized prostate cancer, a BMD test followed by selective alendronate for those with osteoporosis is a cost-effective use of resources. Routine use of alendronate without a BMD test is justifiable in patients at higher risk for hip fractures.