title: Androgen deprivation therapy in prostate cancer: are rising concerns leading to falling use?
abstract: OBJECTIVE
  To describe patterns of initiation of androgen deprivation therapy (ADT) in a population-based cohort of patients with prostate cancer.
  
  
  METHODS
  All patients with prostate cancer in Ontario, Canada, who started ≥90 days of ADT at age ≥66 years in 1995-2005 were classified by ADT regimen: medical castration [oestrogen and/or luteinizing hormone-releasing hormone (LHRH) agonist); orchidectomy; antiandrogen monotherapy; combined androgen blockade (CAB) medical (medical castration plus antiandrogen); CAB surgical (orchidectomy plus antiandrogen). Indications for ADT were as follows: neoadjuvant (short-term before prostatectomy or radiation therapy); adjuvant (long-term with prostatectomy or radiation therapy); metastatic disease; biochemical recurrence; primary (localized disease); other. We examined trends in ADT regimen and indication over time.
  
  
  RESULTS
  The number of patients initiating ADT increased from 1995 to 2001 (2106-2916 per year) and declined thereafter to 2200-2300 annually (total n= 26,809). However, prostate cancer prevalence doubled over these years, and the rate of ADT initiation decreased from 16 to 7 per 100 person-years. Patterns varied by regimen and indication. Medical castration increased from 12% of all ADT in 1995 to 47% in 2005; orchidectomy decreased from 17 to 4%. Use for metastatic disease remained stable, but adjuvant therapy increased from <3% of all ADT in 1995 to 13% in 2005. Primary therapy was the most common indication, but decreased over time.
  
  
  CONCLUSIONS
  ADT initiation has fallen and marked changes occurred in treatment patterns for prostate cancer. Changes might be driven by increasing awareness of potential harms and costs, and by new evidence supporting ADT for specific indications.
authors: Toronto General Research Institute, Canada.
authors: Murray
authors: M
authors: Krahn
authors: Karen E
authors: KE
authors: Bremner
authors: George
authors: G
authors: Tomlinson
authors: Jin
authors: J
authors: Luo
authors: Paul
authors: P
authors: Ritvo
authors: Gary
authors: G
authors: Naglie
authors: Shabbir M H
authors: SM
authors: Alibhai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant / Q000706:statistics & numerical data; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors; D006801:Humans; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy; D009864:Ontario / Q000453:epidemiology; D009919:Orchiectomy / Q000706:statistics & numerical data; D015995:Prevalence; D011468:Prostatectomy / Q000706:statistics & numerical data; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000453:epidemiology / Q000601:surgery; D013997:Time Factors
chemical_list: D000726:Androgen Antagonists; D007987:Gonadotropin-Releasing Hormone