Examine the impact of different definitions of castration resistance used to identify patients with castration-resistant prostate cancer (CRPC) using electronic health records (EHR).
CRPC is a form of prostate cancer that is resistant to treatment with androgen deprivation therapy (ADT) and is associated with higher morbidity and mortality. Widely used guidelines like the Prostate Cancer Working Group 3 (PCWG 3), the American Urological Association (AUA), and many others differ in their definitions of castration-resistance. Until now, the feasibility of identifying CRPC using different definitions from EHR data has not been studied.
EHR data from the Veterans Health Administration (01/2006-12/2020) were used to identify veterans with CRPC according to the following criteria: 1) PCWG 3—a PSA increase ?25% from the nadir with a minimum rise of 2 ng/mL, while castrate (testosterone < 50 ng/mL); 2) AUA—2 consecutive PSA rises of ?0.2 ng/mL; 3) CRPC screening—a PSA rise of > 0.0 ng/mL within a window of 7–90 days.
36,101 unique patients were identified using 1 of (or a combination of) the 3 CRPC criteria. Approximately 12,775 (35%) patients met all 3 criteria, while 8,589 (24%) were identified by AUA, 4,785 (13%) by CRPC screening, and 145 (0.4%) by PCWG3. A total of 8,377 (23%) patients met both the AUA and CRPC screening criteria, 1,219 (3%) patients met the AUA and PCWG3 criteria, and 211 (1%) met the PCWG3 and CRPC screening criteria.
Although several definitions can be used to identify CRPC patients, a combination of these definitions results in the greatest yield of CRPC patients identified using EHR data. Even though the PCWG3 criterion is frequently used in both clinical trials research and retrospective observational research, PCWG3 may miss many patients meeting other criteria and should not be used by itself when studying patients with CRPC identified from EHR data.