title: Duration of Androgen Deprivation Therapy Influences Outcomes for Patients Receiving Radiation Therapy Following Radical Prostatectomy.
abstract: BACKGROUND
  Limited data exist to guide the use of androgen deprivation therapy (ADT) for men treated with radiation therapy (RT) after radical prostatectomy (RP). The optimal duration of ADT in this setting is unknown.
  
  
  OBJECTIVE
  To determine if the duration of ADT influences clinical outcomes for men receiving post-RP RT.
  
  
  METHODS
  A total of 680 men who received adjuvant radiation therapy (n=105) or salvage radiation therapy (n=575) between 1986 and 2010 at a single tertiary care institution were reviewed retrospectively. Median follow-up post-RT was 57.8 mo.
  
  
  METHODS
  RT was delivered using three-dimensional conformal or intensity-modulated RT in 1.8-Gy fractions. For patients treated with ADT, >80% were treated with a gonadotropin-releasing hormone agonist with or without a nonsteroidal antiandrogen.
  
  
  METHODS
  Biochemical failure (BF), distant metastasis (DM), prostate cancer-specific mortality (PCSM), and overall mortality were assessed using Kaplan-Meier analysis and propensity score analysis.
  
  
  CONCLUSIONS
  Overall, 144 patients (21%) received ADT with post-RP RT, most of whom had high-risk disease features such as Gleason score 8-10, seminal vesicle invasion, or pre-RT prostate-specific antigen >1 ng/ml. Median ADT duration was 12 mo (interquartile range: 6.0-23.7). Patients who received <12 mo of ADT had an association with increased BF (hazard ratio [HR]: 2.27; p=0.003) and DM (HR: 2.48; p=0.03) compared with patients receiving ≥12 mo of ADT. The 5-yr rates of DM were 6.0% and 23% for ≥12 and <12 mo of ADT, respectively. On propensity score analysis controlling for pretreatment and treatment-related factors, each month of ADT was associated with a decreased risk for BF (HR: 0.95; p=0.0004), DM (HR: 0.88; p=0.0004), and PCSM (HR: 0.90; p=0.037). These findings are limited by the retrospective nature of our analysis.
  
  
  CONCLUSIONS
  For men with high-risk disease features receiving ADT with post-RP RT, the duration of ADT is associated with clinical outcomes. Our findings suggest that for these men an extended course of ADT ≥12 mo may be preferable. Validation of our findings is needed.
  
  
  RESULTS
  We evaluated outcomes for men with high-risk disease features treated with androgen deprivation therapy (ADT) and radiotherapy after radical prostatectomy. Longer durations of ADT resulted in improved patient outcomes.
authors.affiliation: Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI, USA.
authors.forename: William C
authors.initials: WC
authors.lastname: Jackson
authors.affiliation: Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Schipper
authors.affiliation: Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI, USA.
authors.forename: Skyler B
authors.initials: SB
authors.lastname: Johnson
authors.affiliation: Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI, USA.
authors.forename: Corey
authors.initials: C
authors.lastname: Foster
authors.affiliation: Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI, USA.
authors.forename: Darren
authors.initials: D
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, Cedars-Sinai, Los Angeles, CA, USA.
authors.forename: Howard M
authors.initials: HM
authors.lastname: Sandler
authors.affiliation: Department of Urology, University of Michigan Medical Center, Ann Arbor, MI, USA.
authors.forename: Ganesh S
authors.initials: GS
authors.lastname: Palapattu
authors.affiliation: Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Hamstra
authors.affiliation: Department of Radiation Oncology, University of Michigan Medical Center, Ann Arbor, MI, USA. Electronic address: ffeng@med.umich.edu.
authors.forename: Felix Y
authors.initials: FY
authors.lastname: Feng
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000008:administration & dosage*; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D017024:Chemotherapy, Adjuvant; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D057216:Propensity Score; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000628:therapy*; D018714:Radiotherapy, Adjuvant; D050397:Radiotherapy, Intensity-Modulated; D012189:Retrospective Studies; D016879:Salvage Therapy; D015996:Survival Rate
chemical_list: D000726:Androgen Antagonists; D000970:Antineoplastic Agents; D007987:Gonadotropin-Releasing Hormone; D017430:Prostate-Specific Antigen
keywords: Androgen deprivation therapy; Postprostatectomy radiotherapy; Prostate cancer