International comparison of androgen-deprivation therapy (ADT) for the treatment of nonmetastatic (M0) prostate cancer (PC).

Abstract

e16040 Background: ADT represents standard of care for PC patients (pts) with signs of recurrence after primary therapy (tx). Nature and extent of ADT among M0 pts is not well-characterized, and nearly all ADT-treated pts relapse to develop castration-resistant PC (CRPC) after a median 18-24 months (mos) (Felici 2012). This physician survey quantifies ADT in populations with high or increasing incidence of M0 PC (Ferlay 2010). Methods: A 45-minute online survey was completed by urology and oncology practitioners (MDs) from 19 countries. Eligibility ensured MDs were responsible for tx decisions in the care of M0 PC, and had ≥10 pts on ADT. MDs were asked about tx at different points in the PC pathway, focusing on ADT (gonadotropin-releasing hormone [GnRH] or bilateral orchiectomy [bil orch]), type and duration of GnRH (intermittent vs. continuous), concurrent tx, and pts with CRPC (high risk CRPC definitions explored). Results: In total, 441 MDs completed the survey; predominantly urologists (88%). MDs had 98,689 PC pts under their care, 76,386 (77%) M0 PC. Of M0 PC, 38% received ADT: 37% (28104) GnRH (mainly leuprorelin [47%] or goserelin [21%]) and 1.6% (1251) bil orch (Table). The 34% tx rate reported by US MDs is consistent with decreasing ADT use (Shahinian 2010), whereas rates remain higher in Europe, particularly for Eastern European pts. Across regions, 74% (20,729) of GnRH pts received ≥6 mos, 48% (13,594) continuously; of these, 71% were expected to develop CRPC, 57% of CRPC were considered high risk for bone metastasis (BM). PSA doubling time ≤6 mos was most commonly cited high risk definition. Conclusions: These findings further our understanding of ADT use among M0 PC, which differs by country, by region, with highest rates reported in Europe. ADT rates have public health implications on the number of men expected to develop CRPC and be at high risk of BM in the future. [Table: see text]