GNRH1 and prostate cancer: However, our case adds support to the suggestion of Raddin and colleagues (2011) that when prostate cancer has become resistant to ADT on a combination of AA and a GnRH agonist, a GnRH antagonist may offer a nonsurgical alternative; in these cases, APs in oncology may advocate for a trial of a GnRH antagonist before surgical castration is considered.