Prevalence study of intermittent hormonal therapy of Prostate Cancer patients in Spain.

Although intermittent androgen deprivation therapy was introduced many years ago to improve patients' quality of life with the same carcinologic efficiency as continuous hormonal therapy, recent data suggest that intermittency could be underutilised. This study aims to estimate the prevalence of prostate cancer patients receiving intermittent androgen deprivation therapy in Spain. A retrospective, longitudinal study was conducted using electronic drug dispensation data from four Spanish autonomous communities, which encompass 17.23 million inhabitants (36.22% of the total population in Spain). We estimated intermittent androgen therapy use (%IAD) and the prevalence of patients under intermittent androgen therapy in reference to the total number of PC patients using hormonal therapy (P ) and stratified by region. Other outcome variables included the pharmaceutical forms dispensed and the total direct annual expenditure on androgen deprivation therapy-associated medications. A total of 863,005 dispensations corresponding to a total of 65,752 men were identified, treated with either luteinizing hormone-releasing hormone (LHRH) analogues (353,162) administered alone or in combination with anti-androgens (509,843). Overall, the mean (±SD) age of the patients was 76.9 (±10.4) years. Results revealed that the mean annual P along the study was 6.6% in the total population studied, and the overall %IAD during the five-year study period was 5.6%. The mean cost of hormonal therapy per year was 25 million euros for LHRH analogues and 6.3 million euros for anti-androgens.  Few prostate cancer patients in Spain use the intermittent androgen deprivation therapy suggesting underutilization of a perfectly valid option for a significant proportion of patients, missing the opportunity to improve their quality of life and to reduce costs for the National Health Service with comparable overall survival rates than continuous therapy.