title: Very high-risk prostate cancer: stratification by outcomes of radiotherapy and long-term androgen deprivation therapy.
abstract: OBJECTIVE
  The definition of very high-risk (VHR) prostate cancer is currently based on the study of radical prostatectomy. We aimed to identify a suitable definition for VHR group following external beam radiation therapy (EBRT) and long-term androgen-deprivation therapy (ADT).
  
  
  METHODS
  This retrospective study included 356 high-risk patients treated with EBRT and long-term ADT. A median follow-up time was 68 months. At first, associations of previously described prognostic factors with biochemical disease-free survival (bDFS), clinical relapse-free survival (cRFS) and prostate cancer-specific survival (CSS) were examined. Second, the combination of significant adverse factors in the first analysis served as VHR test definitions. For each factor, a Cox proportional hazards model was used to calculate their hazard ratios for bDFS and cRFS. The logrank test was used to evaluate the association between each factor and CSS.
  
  
  RESULTS
  Primary Gleason pattern 5, T4 and ≥ 5 or 4 cores with Gleason score 8-10 were risk factors associated with bDFS, cRFS and CSS. Eleven VHR test definitions composed of these adverse factors were associated significantly with bDFS, cRFS and CSS. The final definition was described by primary Gleason pattern 5 or T4 or ≥ 4 cores with Gleason score 8-10 because of the largest sample size of 38% among 11 test definitions. bDFS, cRFS and CSS of the VHR group were significantly lower compared with other high-risk patients (P < 0.001, P < 0.001 and P = 0.015, respectively).
  
  
  CONCLUSIONS
  These VHR criteria were best fitted following EBRT with long-term ADT.
authors.affiliation: Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Natsuo
authors.initials: N
authors.lastname: Tomita
authors.affiliation: Department of Urology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Norihito
authors.initials: N
authors.lastname: Soga
authors.affiliation: Department of Urology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ogura
authors.affiliation: Department of Urology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Kageyama
authors.affiliation: Department of Radiation Oncology, Aichi Cancer Center Hospital, Nagoya, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kodaira
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use*; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D000726:Androgen Antagonists
keywords: androgen deprivation therapy; prostate cancer; radiotherapy; risk stratification; very high-risk