title: Clinical outcomes and nadir prostate-specific antigen (PSA) according to initial PSA levels in primary androgen deprivation therapy for metastatic prostate cancer.
abstract: OBJECTIVE
  To investigate the clinical outcomes of metastatic prostate cancer patients and the relationship between nadir prostate-specific antigen (PSA) levels and different types of primary androgen deprivation therapy (PADT). This study utilized data from the Japan Study Group of Prostate Cancer registry, which is a large, multicenter, population-based database.
  
  
  METHODS
  A total of 2982 patients treated with PADT were enrolled. Kaplan-Meier analysis was used to compare progression-free survival (PFS) and overall survival (OS) in patients treated using combined androgen blockade (CAB) and non-CAB therapies. The relationships between nadir PSA levels and PADT type according to initial serum PSA levels were also investigated.
  
  
  RESULTS
  Among the 2982 enrolled patients, 2101 (70.5 %) were treated with CAB. Although CAB-treated patients had worse clinical characteristics, their probability of PFS and OS was higher compared with those treated with a non-CAB therapy. These results were due to a survival benefit with CAB in patients with an initial PSA level of 500-1000 ng/mL. Nadir PSA levels were significantly lower in CAB patients than in non-CAB patients with comparable initial serum PSA levels.
  
  
  CONCLUSIONS
  A small survival benefit for CAB in metastatic prostate cancer was demonstrated in a Japanese large-scale prospective cohort study. The clinical significance of nadir PSA levels following PADT was evident, but the predictive impact of PSA nadir on OS was different between CAB and non-CAB therapy.
authors.affiliation: Department of Integrative Cancer Therapy and Urology, Graduate School of Medical Science, Kanazawa University, Takaramachi 13-1, Kanazawa, Ishikawa, 920-8640, Japan. yasukita@med.kanazawa-u.ac.jp.
authors.forename: Yasuhide
authors.initials: Y
authors.lastname: Kitagawa
authors.affiliation: Department of Integrative Cancer Therapy and Urology, Graduate School of Medical Science, Kanazawa University, Takaramachi 13-1, Kanazawa, Ishikawa, 920-8640, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Ueno
authors.affiliation: Department of Integrative Cancer Therapy and Urology, Graduate School of Medical Science, Kanazawa University, Takaramachi 13-1, Kanazawa, Ishikawa, 920-8640, Japan.
authors.forename: Kouji
authors.initials: K
authors.lastname: Izumi
authors.affiliation: Department of Integrative Cancer Therapy and Urology, Graduate School of Medical Science, Kanazawa University, Takaramachi 13-1, Kanazawa, Ishikawa, 920-8640, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Kadono
authors.affiliation: Department of Integrative Cancer Therapy and Urology, Graduate School of Medical Science, Kanazawa University, Takaramachi 13-1, Kanazawa, Ishikawa, 920-8640, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Mizokami
authors.affiliation: Center of Innovative Clinical Medicine, Okayama University, Okayama, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Hinotsu
authors.affiliation: Department of Strategic Investigation on Comprehensive Cancer Network Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Akaza
authors.affiliation: Department of Integrative Cancer Therapy and Urology, Graduate School of Medical Science, Kanazawa University, Takaramachi 13-1, Kanazawa, Ishikawa, 920-8640, Japan.
authors.forename: Mikio
authors.initials: M
authors.lastname: Namiki
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use*; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000097:blood; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D009362:Neoplasm Metastasis; D011159:Population Surveillance / Q000379:methods*; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000556:secondary; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000726:Androgen Antagonists; D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen
keywords: Combined androgen blockade; Nadir PSA level; Outcome predictor; Primary androgen deprivation; Prostate cancer