title: Intermittent androgen ablation in patients with biochemical failure after pelvic radiotherapy for localized prostate cancer.
abstract: OBJECTIVE
  To assess the efficacy of intermittent androgen ablation (IAA) in patients with biochemical failure after radiotherapy for prostate cancer.
  
  
  METHODS
  Thirty-nine patients received a luteinizing hormone-releasing hormone analog every 2 months for a total of 4 doses. IAA was then discontinued if serum prostate-specific antigen (PSA) fell to a normal level with a castrate level of testosterone. Therapy was restarted when the serum PSA level reached > or = 10 ng/mL and was discontinued if hormone resistance or unacceptable toxicity occurred.
  
  
  RESULTS
  Median PSA was 9.1 ng/mL at the time of first IAA. The median time between the first and the second cycles was 20.1 months, decreasing to 15.5 months between the third and fourth cycles. Two patients discontinued the treatment because of severe hot flushes. Four patients developed hormone resistance. With a median follow-up of 56.4 months, 5-year survival is 92.3%. Three patients died of unrelated causes. The incidence of distant metastasis is 6.8%.
  
  
  CONCLUSIONS
  The use of IAA seems to be a safe and effective treatment for patients with biochemical failure post radiotherapy and no evidence of metastatic disease. The use of IAA limits hormone-related side effects and health care costs without an apparent increase in the risk for the development of metastatic disease.
authors.affiliation: Department of Oncology, Division of Radiation Oncology, McGill University, Montreal, Quebec, Canada.
authors.forename: Fabio L B
authors.initials: FL
authors.lastname: Cury
authors.forename: Luis
authors.initials: L
authors.lastname: Souhami
authors.forename: Raghu
authors.initials: R
authors.lastname: Rajan
authors.forename: Simon
authors.initials: S
authors.lastname: Tanguay
authors.forename: Bruno
authors.initials: B
authors.lastname: Gagnon
authors.forename: Marie
authors.initials: M
authors.lastname: Duclos
authors.forename: George
authors.initials: G
authors.lastname: Shenouda
authors.forename: Sergio L
authors.initials: SL
authors.lastname: Faria
authors.forename: Marc
authors.initials: M
authors.lastname: David
authors.forename: Carolyn R
authors.initials: CR
authors.lastname: Freeman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000009:adverse effects / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000009:adverse effects / Q000627:therapeutic use*; D002064:Buserelin / Q000627:therapeutic use*; D019008:Drug Resistance, Neoplasm; D019584:Hot Flashes / Q000139:chemically induced; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000532:radiotherapy; D011788:Quality of Life; D012016:Reference Values; D013739:Testosterone / Q000097:blood
chemical_list: D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D013739:Testosterone; D017430:Prostate-Specific Antigen; D002064:Buserelin