Cost-effectiveness of fracture prevention in men who receive androgen deprivation therapy for localized prostate cancer

Abstract

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.

Figure. Clinical strategies and progression model for prostate cancer

ADT = androgen deprivation therapy; BMD = bone mineral density; PSA = prostate-specific antigen. Top. Algorithm showing a decision made at the onset of ADT for localized prostate cancer. Patients assigned to the alendronate group received alendronate for 5 years after proceeding to the prostate cancer progression model. Bottom. Prostate cancer progression model. Patients enter the model with localized disease. Each year, patients are at risk for the progression of prostate cancer, the occurrence of a hip fracture, or both. Throughout the patients’ lifetime, all patients are at risk for death from causes unrelated to prostate cancer (not shown by the state or arrows). Squares represent the health states in the model. Arrows represent transitions between health states.