Variation in Use of Androgen Suppression With External-Beam Radiotherapy for Nonmetastatic Prostate Cancer

Purpose To describe practice patterns associated with androgen suppression (AS) stratified by disease risk group in patients undergoing external-beam radiotherapy (EBRT) for localized prostate cancer. Methods and Materials We identified 2,184 low-risk, 2,339 intermediate-risk, and 2,897 high-risk patients undergoing EBRT for nonmetastatic prostate cancer diagnosed between January 1, 2004, and December 31, 2005, in the linked Surveillance, Epidemiology, and End Results—Medicare database. We examined the association of patient, clinical, and demographic characteristics with AS use by multivariate logistic regression. Results The proportions of patients receiving AS for low-risk, intermediate-risk, and high-risk prostate cancer were 32.2%, 56.3%, and 81.5%, respectively. AS use among men in the low-risk disease category varied widely, ranging from 13.6% in Detroit to 47.8% in Kentucky. We observed a significant decline in AS use between 2004 and 2005 within all three disease risk categories. Men aged ≥75 years or with elevated comorbidity levels were more likely to receive AS. Conclusion Our results identified apparent overuse and underuse of AS among men within the low-risk and high-risk disease categories, respectively. These results highlight the need for clinician and patient education regarding the appropriate use of AS. Practice patterns among intermediate-risk patients reflect the clinical heterogeneity of this population and underscore the need for better evidence to guide the treatment of these patients.