A change from gonadotropin releasing hormone antagonist to gonadotropin releasing hormone agonist therapy does not affect the oncological outcomes in hormone sensitive prostate cancer

BACKGROUND: The aim of our retrospective study was to evaluate the 5-year survival and time to castration resistant prostate cancer in patients with hormone sensitive prostate cancer treated with the gonadotropin releasing hormone antagonist, degarelix. Another aim was to evaluate the effects of changing the treatment from degarelix to a gonadotropin releasing hormone agonist after achieving stable disease control, on the clinical and oncological outcomes. RESULTS: Our analysis was based on the data of 108 patients with prostate cancer who were treated with degarelix. Of these, the treatment was changed from degarelix to a gonadotropin releasing hormone agonist in 57 patients (changed group), and the treatment with degarelix was continued in the other 51 (continued group). The overall 5-year survival was statistically superior in the changed (96.6%) group than that in the continued (74.1%) group (p = 0.006). The 5-year cancer-specific survival was also superior in the changed (100%) group than that in the continued (84.6%) group (p = 0.027). The average time to castration resistant prostate cancer was comparable in both the changed (43.3 months) and continued (35.2 months) groups (p = 0.117). Lower serum levels of prostate specific antigen and alkaline phosphatase were maintained after changing the therapy from degarelix to a gonadotropin releasing hormone agonist. CONCLUSIONS: Degarelix is effective in the treatment of prostate cancer. Degarelix therapy can also be safely changed to a gonadotropin releasing hormone agonist without any adverse clinical or oncological effects.