Prostatic Neoplasms

Inclusion Criteria

- Enrolled in both Medicare Parts A and B for at least 1 year before the cohort entry date (minimum lookback period for comorbidities and treatments)
 - Primary site code of prostate cancer (International Classification of Diseases for Oncology, Third Edition [ICD-O-3] topography code C61.9) in SEER data
 - Surgical castration or androgen deprivation therapy after prostate cancer diagnosis; androgen deprivation therapy will be indicated by the use of any of the following drugs: abarelix, bicalutamide, buserelin, cyproterone, degarelix, diethylstilbestrol, estramustine, flutamide, gonadorelin, goserelin, histrelin, leuprolide, medroxyprogesterone, megestrol, nafarelin, nilutamide, polyestradiol, triptorelin
 - Evidence that prostate cancer was resistant to surgical castration or androgen deprivation therapy (“castration-resistant prostate cancer”), as indicated by starting one of the following second-line systemic therapies (cohort entry date): abiraterone, cabazitaxel, docetaxel, enzalutamide, mitoxantrone, or sipuleucel-T
 - Cohort entry date 01 January 2006 or later
 - Age 65 years or older in the US on the cohort entry date

Exclusion Criteria

- Enrollment in an HMO (Health Maintenance Organization) in the year before the cohort entry date
 - Diagnosis of any cancer other than prostate cancer or nonmelanoma skin cancer on or before the cohort entry date
 - Any diagnostic code for metastases other than bone metastases or lymph node metastases on or before the cohort entry date
 - Any claim for treatment with Xofigo on or before the cohort entry date.