title: A multicenter retrospective analysis of sequential treatment of abiraterone acetate followed by docetaxel in Japanese patients with metastatic castration-resistant prostate cancer.
abstract: OBJECTIVE
  Abiraterone acetate and docetaxel are promising treatment options for metastatic castration-resistant prostate cancer patients. However, the optimal sequencing of these agents is unclear, and no previous reports discuss Japanese metastatic castration-resistant prostate cancer patients. The purpose of this analysis is to reveal the outcomes of Japanese metastatic castration-resistant prostate cancer patients treated with abiraterone acetate followed by docetaxel.
  
  
  METHODS
  We retrospectively reviewed Japanese Phase 1 and Phase 2 trials of metastatic castration-resistant prostate cancer patients treated with abiraterone acetate until disease progression and subsequently treated with docetaxel. The primary outcome measure was the rates of prostate-specific antigen declines ≧30 and ≧50%, respectively, with docetaxel. Secondary outcome measures included progression-free survival with docetaxel, and overall survival after initiation of abiraterone acetate and docetaxel. We performed correlation analysis between previous prostate-specific antigen response to abiraterone acetate and subsequent prostate-specific antigen response to docetaxel.
  
  
  RESULTS
  We identified 15 patients had experienced disease progression with abiraterone acetate and subsequently were treated with docetaxel. Prostate-specific antigen declines ≧30 and ≧50% with docetaxel were observed in five patients (33%) and two patients (13%), respectively. The median progression-free survival with docetaxel was 3.7 months (95% confidence interval: 2.9-4.6). The median overall survival from initiation of docetaxel and abiraterone acetate were 14.4 months (95% confidence interval: 6.3-22.4), and 25.7 months (95% confidence interval: 20.1-30.7), respectively. No significant correlation was observed between these prostate-specific antigen responses (Pearson r = 0.206, P = 0.46).
  
  
  CONCLUSIONS
  The efficacy of docetaxel in Japanese mCRPC patients that was resistant to abiraterone acetate was modest. The prostate-specific antigen response to previous abiraterone acetate could not predict the efficacy of subsequent docetaxel. Larger prospective trials are needed to validate these findings.
authors.affiliation: Department of Breast and Medical Oncology, National Cancer Center Hospital East, Chiba.
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Ueda
authors.affiliation: Department of Breast and Medical Oncology, National Cancer Center Hospital East, Chiba nmatsuba@east.ncc.go.jp.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Matsubara
authors.affiliation: Division of Urology, Department of Regenerative and Transplant Medicine, Graduate School of Medical and Dental Sciences, Niigata University, Niigata.
authors.forename: Itsuhiro
authors.initials: I
authors.lastname: Takizawa
authors.affiliation: Division of Urology, Department of Regenerative and Transplant Medicine, Graduate School of Medical and Dental Sciences, Niigata University, Niigata.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishiyama
authors.affiliation: Department of Urology, Kitasato University School of Medicine, Kanagawa.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Tabata
authors.affiliation: Department of Urology, Kitasato University School of Medicine, Kanagawa.
authors.forename: Takefumi
authors.initials: T
authors.lastname: Satoh
authors.affiliation: Department of Urology, Toho University Sakura Medical Center, Chiba.
authors.forename: Naoto
authors.initials: N
authors.lastname: Kamiya
authors.affiliation: Department of Urology, Toho University Sakura Medical Center, Chiba.
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Urology, Yokohama City University Graduate School of Medicine, Kanagawa, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawahara
authors.affiliation: Department of Urology, Yokohama City University Graduate School of Medicine, Kanagawa, Japan.
authors.forename: Hiroji
authors.initials: H
authors.lastname: Uemura
mesh_terms: D000069501:Abiraterone Acetate; D000368:Aged; D000736:Androstenes / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D018450:Disease Progression; D018572:Disease-Free Survival; D000077143:Docetaxel; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D064129:Prostatic Neoplasms, Castration-Resistant / Q000097:blood / Q000188:drug therapy* / Q000473:pathology*; D012189:Retrospective Studies; D043823:Taxoids / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D000736:Androstenes; D043823:Taxoids; D000077143:Docetaxel; D017430:Prostate-Specific Antigen; D000069501:Abiraterone Acetate
keywords: PSA; abiraterone; docetaxel; metastatic castration-resistant prostate cancer