title: International survey of androgen deprivation therapy (ADT) for non-metastatic prostate cancer in 19 countries.
abstract: BACKGROUND
  Continuous androgen deprivation therapy (CADT) is commonly used for patients with non-metastatic prostate cancer as primary therapy for high-risk disease, adjuvant therapy together with radiation or for recurrence after initial local therapy. Intermittent ADT (IADT), a recently developed alternative strategy for providing ADT, is thought to potentially reduce adverse effects, but little is known about practice patterns relating to it. We aimed to describe factors related to physicians' ADT use and modality for patients with non-metastatic prostate cancer.
  
  
  METHODS
  A 45 min online survey was completed by urologists and oncologists responsible for treatment decisions for non-metastatic prostate cancer from 19 countries with high or increasing prevalence of non-metastatic prostate cancer.
  
  
  RESULTS
  There were 441 treating physicians who completed the survey which represented 99 177 patients with prostate cancer under their care, of which 76 386 (77%) had non-metastatic prostate cancer. Of patients with non-metastatic prostate cancer, 38% received ADT (37% gonadotropin-releasing hormone (GnRH), 2% orchiectomy); among patients on GnRH, 54% received CADT (≥6 without >3 months interruption), 23% IADT and 23% <6 months. Highest rates of ADT were reported among oncologists (62%) and in Eastern Europe (Czech Republic, Hungary and Poland). Prostate-specific antigen (PSA) levels (65%), Gleason score (52%) and treatment guidelines (48%) were the most common reasons for CADT whereas PSA levels (54%), patient request (48%), desire to maintain sexual function (40%), patient age and comorbidities (38%) were cited most frequently as reasons for IADT.
  
  
  CONCLUSIONS
  This international survey with 441 treating physicians from 19 countries showed that ADT is commonly used in treating patients with non-metastatic prostate cancer, and type of ADT is influenced by high-risk criteria (PSA and Gleason), treatment guidelines and patient preferences. IADT use was primarily driven by PSA levels, patient request and patient age/comorbidities, likely reflecting an attempt to minimise adverse effects of ADT in patients with lower risk tumours.
authors.affiliation: Center for Observational Research, Amgen Inc. , South San Francisco, California , USA.
authors.forename: Alexander
authors.identifier: 0000-0002-7441-4455
authors.initials: A
authors.lastname: Liede
authors.affiliation: Dalla Lana School of Public Health, University of Toronto , Toronto, Ontario , Canada.
authors.forename: David C
authors.initials: DC
authors.lastname: Hallett
authors.affiliation: Adelphi Research , Macclesfield , UK.
authors.forename: Kirsty
authors.initials: K
authors.lastname: Hope
authors.affiliation: Adelphi Research , Macclesfield , UK.
authors.forename: Alex
authors.initials: A
authors.lastname: Graham
authors.affiliation: Global Health Economics , Amgen Inc. , Thousand Oaks, California , USA.
authors.forename: Jorge
authors.initials: J
authors.lastname: Arellano
authors.affiliation: Department of Internal Medicine , University of Michigan , Ann Arbor, Michigan , USA.
authors.forename: Vahakn B
authors.initials: VB
authors.lastname: Shahinian
keywords: androgen deprivation therapy; international survey; nonmetastatic prostate cancer; physician survey; urologic oncologist