Overuse of imaging for staging low risk prostate cancer

Abstract

Purpose: Routine imaging for staging low risk prostate cancer is not recommended according to current guidelines. We characterized patterns of care and factors associated with imaging overuse.

Materials and methods: We used SEER-Medicare linked data to identify men diagnosed with low risk prostate cancer from 2004 to 2005, and determined if imaging (computerized tomography, magnetic resonance imaging, bone scan, abdominal ultrasound) was obtained following prostate cancer diagnosis before treatment.

Results: Of the 6,444 men identified with low risk disease 2,330 (36.2%) underwent imaging studies. Of these men 1,512 (23.5%), 1,710 (26.5%) and 118 (1.8%) underwent cross-sectional imaging (computerized tomography or magnetic resonance imaging), bone scan and abdominal ultrasound, respectively. Radiation therapy vs surgery was associated with greater odds of imaging (OR 1.99, 95% CI 1.68-2.35, p <0.01), while active surveillance vs surgery was associated with lower odds of imaging (OR 0.44, 95% CI 0.34-0.56, p <0.01). Associated with increased odds of imaging was median household income greater than $60,000 (OR 1.41, 95% CI 1.11-1.79, p <0.01), and men from New Jersey vs San Francisco (OR 3.11, 95% CI 2.24-4.33, p <0.01) experienced greater odds of imaging. Men living in areas with greater than 90% vs less than 75% high school education experienced lower odds of imaging (OR 0.76, 95% CI 0.6-0.95, p = 0.02).

Conclusions: There is widespread overuse and significant geographic variation in the use of imaging to stage low risk prostate cancer. Moreover treatment associated variation in imaging was noted with the greatest vs lowest imaging use observed for radiation therapy vs active surveillance.