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Androgen deprivation therapy (ADT) has been the standard therapy used to manage the symptoms of metastatic prostate cancer for decades, yet little is known about differences in the use of various forms of ADT over time. Thus, the objective of this study was to investigate individual and clinical factors associated with the diffusion of an innovative ADT (luteinizing hormone-releasing hormone (LHRH) agonists) and a traditional ADT (bilateral orchiectomy). Data from the Surveillance, Epidemiology, and End Results (SEER)-Medicare combined dataset examined 5,273 African-American and Caucasian men, ages 65 years and older, diagnosed with stage IV prostate cancer during 1991-1999. Modified Poisson regression was used to assess the individual and clinical factors associated with the receipt of LHRH agonists or orchiectomy, using no ADT as the referent. The majority of men diagnosed with metastatic prostate cancer during 1991-1999 did receive an LHRH agonist or an orchiectomy, while 28% did not receive either form of ADT. During the study period, the use of orchiectomy declined and the use of LHRH agonists increased for both African-American and Caucasian men (p for trend<0.001). However, using no ADT as the referent, African-American men were less likely to receive an LHRH agonist (RR=0.84, 95% CI=0.76, 0.93) or an orchiectomy (RR=0.80, 95% CI=0.73, 0.87) in multivariate analysis adjusted for age, race, marital status, diagnosis year, SEER geographic location, and Gleason grade. Additional adjustment for the Charlson comorbidity index attenuated these associations, but the racial differences persisted and remained significant for both forms of ADT. In summary, the adoption of LHRH agonists and the use of orchiectomy lagged among African-American men compared to Caucasian men during the 1990s, and African-American men were less likely to receive either the new or old modalities of ADT despite the availability of Medicare reimbursement. Future studies should investigate reasons for these differences, along with additional factors that may influence patients' decisions to use particular forms of ADT and physicians' decisions to recommend them for the management of metastatic prostate cancer.

98th AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA