e15147 Background: Androgen deprivation therapy (ADT) is the cornerstone treatment of advanced PC, but is frequently used in the M0 setting. After a variable period of hormone-sensitivity, most patients develop CR disease (rising prostate-specific antigen [PSA] despite ongoing ADT). These men are at increased risk of developing bone metastases (BMT), particularly in those with higher serum PSA and shorter PSA doubling time (DT). The epidemiology and natural history of M0 CRPC has not been well-studied in a population-based setting. Methods: A retrospective cohort study was conducted using HFHS administrative data and included 691 men diagnosed with M0 PC between 1996 and 2005, who received ADT, with serial PSA measurements to determine CR. Patient records through 12/31/2008 were reviewed for outcomes of interest. CRPC was defined as 2 consecutive PSA rises, with “high risk” defined as PSA ≥8 ng/mL or PSA DT ≤10 months (mos) after the development of CRPC (Smith MR et al. Lancet 379:39-46, 2012). The risk of BMT was estimated for the entire cohort and for the CRPC and high-risk CRPC subsets. Results: Of the 691 patients included in the cohort (median age: 73 years, 48% African American), 98% received only GnRH agonists and 2% had orchiectomy. Median follow-up for the entire cohort after ADT initiation was 49 mos (IQR=45). 101 patients (15%) met criteria for CRPC during follow-up, with a median of 18 mos on active ADT prior to CRPC development (IQR=14). Of CRPC patients, 85% met criteria for high-risk (of those, 16% had PSA ≥8 ng/mL, 12% had PSA DT ≤10 mos, and 72% had both). Among all patients, 12% (n=82) developed BMT during follow-up, with 42% (n=36) of the high-risk CRPC subset developing BMT. Median time from high-risk CRPC to BMT was 9 mos (IQR=17). Conclusions: The HFHS resource allowed for our investigation of PSA characteristics corresponding to disease progression in a racially diverse patient population. A substantial proportion of M0 PC patients on ADT will eventually develop CR disease. Once a patient has CRPC, the risk of BMT is relatively high.
Factors Related to Prostate-Specific Antigen–Based Prostate Cancer Screening in Primary Care: Retrospective Cohort Study of 120,587 French Men Over the Age of 50 Years
