Medication utilization evaluation of androgen deprivation therapy for prostate cancer in Taiwan

Prostate cancer is one of the most common cancer in males. Both the incidence and the mortality rates of prostate cancer show an increasing trend. Androgen deprivation therapy (ADT) is the standard treatment for metastatic prostate cancer. The aim of our study was to show the epidemiology of prostate cancer and the proportion of patients utilizing ADT. This study used Taiwan's National Health Insurance Research Database (NHIRD) and identified the patients who had been diagnosed with prostate cancer (International Classification of Disease (ICD)-10: C61) and followed up between Jan 1, 2008 and Dec 31, 2015. The ADT drugs used by prostate cancer patients were recorded: Gonadotropin-releasing hormone (GnRH) agonists; GnRH antagonist; estrogen analogs and androgen receptor antagonist. A total of 25,233 patients with newly diagnosed prostate cancer in 2008-2014 were enrolled. The utilization of ADT increased from more than 7,000 person-time in 2008 to more than 50,000 person-time in 2014. Cyproterone acetate was the most commonly used drug in 2008-2015, but its proportion of utilization, which was the highest in stage 2 cancer, dropped from 43% in 2008 to 15% in 2015. Bicalutamide was the second most used drug from 2008 to 2015, but its utilization was not different for different stages. The incidence rate of prostate cancer increased in the study period and medical expenditure also increased in ADT treatment. Health insurance benefits for various ADT drugs should be further evaluated.