Failure of gonadotropin-releasing hormone agonists with and without sterile abscess formation at depot sites: insight into mechanisms?

We describe a patient with advanced prostate cancer who failed to achieve testosterone suppression with depot leuprolide after developing sterile abscesses at the injection sites. When the patient was switched to depot goserelin, he did not have any evidence of inflammation at the injection sites, but testosterone suppression again failed. This case suggests variable mechanisms for failure of gonadotropin-releasing hormone agonist therapy and highlights the necessity of prospective testosterone monitoring in patients who have developed sterile abscesses, even if switched to another gonadotropin-releasing hormone agonist.