Androgen deprivation therapy (ADT) use in Medicare beneficiaries with nonmetastatic (M0) prostate cancer (PC) in the United States.

e15169 Background: ADT is well-established for metastatic PC but is also used in men with less advanced PC. Patterns of ADT use in the M0 PC setting have not been well-described. Methods: Medicare claims in 2005 for men aged ≥66 years (yrs) were assessed for use of gonadotropin-releasing hormone agonists or bilateral orchiectomy. The cohort was limited to men who, during the 15 months (mos) prior to their first 2005 ADT claim, had continuous Parts A + B coverage, a diagnosis code for PC, no claims for metastases (except lymph nodes), and no claims for ADT. Follow-up (f/u) was from ADT initiation to 3 yrs, death, or change in Medicare coverage. Regimen duration was defined by combining claim service count and dosage with FDA label dosing. Because ADT has biologic activity beyond the recommended regimen duration, active dose time was calculated by adding 3 and 6 mos to claims for regimens <6 mos and ≥6 mos, respectively. Interruption was defined as ≥180 days from end of active dose time to next ADT claim. R...