Association of Bone Mineral Density Testing With Risk of Major Osteoporotic Fractures Among Older Men Receiving Androgen Deprivation Therapy to Treat Localized or Regional Prostate Cancer

Abstract

Bone health screening is recommended for patients with prostate cancer who are initiating treatment with androgen deprivation therapy (ADT); however, bone mineral density screening rates in the US and their association with fracture prevention are unknown. To assess dual-energy x-ray absorptiometry (DXA) screening rates and their association with fracture rates among older men with prostate cancer initiating treatment with androgen deprivation therapy. This retrospective nationwide population-based cohort study used data from the Surveillance, Epidemiology, and End Results database and the Texas Cancer Registry linked with Medicare claims. Participants comprised 54 953 men 66 years or older with prostate cancer diagnosed between January 2005 and December 2015 who initiated treatment with ADT. Data were censored at last enrollment in Medicare and analyzed from January 1 to September 30, 2021. Dual-energy x-ray absorptiometry screening within 12 months before and 6 months after the first ADT claim. Frequencies of DXA screening and fracture (any fracture and major osteoporotic fracture) and overall survival were calculated. The association between DXA screening and fracture was evaluated using a multivariable Cox proportional hazards model with propensity score adjustment. Among 54 953 men (median age, 74 years; range, 66-99 years) with prostate cancer, 4689 (8.5%) were Hispanic, 6075 (11.1%) were non-Hispanic Black, 41 453 (75.4%) were non-Hispanic White, and 2736 (5.0%) were of other races and/or ethnicities (including 121 [0.2%] who were American Indian or Alaska Native; 1347 [2.5%] who were Asian, Hawaiian, or Pacific Islander; and 1268 [2.3%] who were of unknown race/ethnicity). Only 4362 men (7.9%) received DXA screening. The DXA screening rate increased from 6.8% in 2005 to 8.4% in 2015. Lower screening rates were associated with being single (odds ratio [OR], 0.89; 95% CI, 0.81-0.97; P = .01) and non-Hispanic Black (OR, 0.80; 95% CI, 0.70-0.91; P < .001), living in small urban areas (OR, 0.77; 95% CI, 0.66-0.90; P = .001) and areas with lower educational levels (OR, 0.75; 95% CI, 0.67-0.83; P < .001), and receiving nonsteroidal androgens (OR, 0.57; 95% CI, 0.39-0.84; P = .004). Overall, 9365 patients (17.5%) developed fractures after initial receipt of ADT. The median time to first fracture was 31 months (IQR, 15-56 months). In the multivariable model with propensity score adjustment, DXA screening was not associated with fracture risk at any site (hazard ratio [HR], 0.96; 95% CI, 0.89-1.04; P = .32) among men without previous fractures before receipt of ADT. However, previous DXA screening was associated with a decreased risk of major fractures (HR, 0.91; 95% CI, 0.83-1.00; P = .05) after propensity score adjustment. In this study, low DXA screening rates were observed among older men with localized or regional prostate cancer after initiation of treatment with ADT. Despite low rates of screening, evaluation of bone mineral density with a DXA scan was associated with lower risk of major fractures. These findings suggest that DXA screening is important for the prevention of major fractures among older men with prostate cancer and that implementation strategies are needed to adopt bone health screening guidelines in clinical practice.