title: Prolonged response to a single androgen suppression phase in a subpopulation of prostate cancer patients.
abstract: BACKGROUND
  In an intermittent androgen suppression therapy (IAS) trial we observed regular cycles of tumor suppression and regrowth in the majority of patients (17 +/- 2.6 month), with a subpopulation of patients (14 of 72) exhibiting a prolonged response of 28 +/- 7 month (range 18-64+ month) to the first eight-month androgen suppression cycle.
  
  
  OBJECTIVE
  To compare clinical data and laboratory tests (testosterone, prostate-specific antigen, and tissue polypeptide-specific antigen) of matched IAS patients showing either regular treatment cycles (n = 16) or prolonged response (n = 14).
  
  
  RESULTS
  Periods of androgen suppression resulted in reversible reduction of serum testosterone (< 1 nmol/l), PSA (< 1 ng/ml) indicating partial growth arrest and apoptotic regression of the tumors. The long-term response subgroup showed significantly lower mean values of tumor gradings, of pretreatment PSA values (11.36 +/- 4.54 vs. 47.5 +/- 12.4 ng/ml PSA), of PSA nadirs during androgen suppression (0.5 vs. 1 ng/ml PSA), and of overall testosterone values (3.9 +/- 1.14 vs. 6.6 +/- 1.18 mmol/l pretreatment) associated with low TPS values.
  
  
  CONCLUSIONS
  Patients exhibiting prolonged response to a single cycle of androgen suppression during IAS are characterized by a lower tumor burden, slow growing and less aggressive tumors, lower testosterone serum concentrations and lower absolute PSA nadirs during androgen suppression compared to a matched control group of short-term responders.
authors.affiliation: Department of Urology, Wilhelminenspital, Vienna, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Theyer
authors.forename: E
authors.initials: E
authors.lastname: Ulsperger
authors.forename: G
authors.initials: G
authors.lastname: Baumgartner
authors.forename: M
authors.initials: M
authors.lastname: Raderer
authors.forename: G
authors.initials: G
authors.lastname: Hamilton
mesh_terms: D000726:Androgen Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000503:physiopathology; D013739:Testosterone / Q000097:blood; D016896:Treatment Outcome
chemical_list: D000726:Androgen Antagonists; D013739:Testosterone; D017430:Prostate-Specific Antigen