Evaluate timeliness of androgen deprivation therapy dosing, impact of dosing non-adherence on testosterone (T) and frequency of T/prostate-specific antigen (PSA) testing in prostate cancer (PCa) patients.

Retrospective analyses of 22,860 PCa patients treated with luteinizing hormone-releasing hormone (LHRH) agonists. Analyses used two definitions of ‘Month’: ’28 Day Month’ (‘Late’: dosing after day 28, 84, 112, or 168) and ‘Extended Month’ (‘Late’ after day 32, 97, 128, or 194) for 1-, 3-, 4-, and 6-month formulations, respectively. Prevalence of ‘Late’ dosing, associated T values and frequency of T/PSA testing were assessed. Statistical significance was tested using unpaired t-test.

84% of injections were ‘Late’ for ’28 Day Month’ and 27% for ‘Extended Month’. For ’28 Day Month’, 60% and 29% of injections were ‘Late’ by >1 and >2 weeks. 4% of T were >50ng/dL for ‘Early/On-Time’ injections using both definitions. 15% and 27% of T were >50ng/dL when ‘Late’, for ’28 Day Month’ and ‘Extended Month’, respectively. For ‘Early/On-Time’ vs. ‘Late’, 22% vs. 31% of T were >20ng/dL for ’28 Day Month’ and 21% vs. 43% for ‘Extended Month’. Mean T were higher when ‘Late’ (49ng/dL for ’28 Day Month’, 79ng/dL for ‘Extended Month’) vs. ‘Early/On-Time’ (21ng/dL for both). 83% of injections had PSA measurements, only 13% a T assessment.

LHRH agonists were frequently (84%) administered later than schedules used in pivotal trials. Nearly half of ‘Late’ T (‘Extended Month’) were >20ng/dL; mean T almost doubled castration level. Elevated T levels remain unidentified with infrequent testing.

The Journal of urology. 2019 Oct 03 [Epub ahead of print]

E David Crawford, Przemyslaw W Twardowski, Raoul S Concepcion, Jason M Hafron, Richard G Harris, Judd W Moul, Lucio N Gordan, Daniel P Petrylak, Stuart Atkinson, Deborah Boldt-Houle, Thomas E Keane, Celestia S Higano, R Jonathan Henderson, A Karim Kader, Maha H Hussain, Neal D Shore

University of California San Diego, California., John Wayne Cancer Institute, California., Integra Connect, Florida., Michigan Institute of Urology, Michigan., UroPartners, Illinois., Duke University, North Carolina., Florida Cancer Specialists, Florida., Yale University, New Haven, Connecticut., Tolmar Pharmaceuticals, Inc., Buffalo Grove, Illinois., Medical University of South Carolina, South Carolina., University of Washington, Washington., Regional Urology, Louisiana., Northwestern University, Illinois., Atlantic Urology Clinics, South Carolina.