title: Impact of the percentage of positive prostate cores on prostate cancer-specific mortality for patients with low or favorable intermediate-risk disease.
abstract: OBJECTIVE
  We investigated whether pretreatment factors predicted time to prostate cancer-specific mortality (PCSM) after conventional-dose and conformal radiation therapy (CRT).
  
  
  METHODS
  Between 1988 and 2002, 421 patients with low (prostate-specific antigen [PSA] level < or = 10 ng/mL and biopsy Gleason score < or = 6) or favorable intermediate-risk (PSA > 10 to 15 ng/mL or biopsy Gleason score 3 + 4, but not both factors) disease underwent CRT (median dose, 70.4 Gy). Cox regression multivariable analysis was performed to determine whether the PSA level, Gleason score, T category, or the percentage of positive cores (% PC) predicted time to PCSM after CRT. After a median follow-up of 4.5 years, 117 (28%) patients have died.
  
  
  RESULTS
  The % PC was the only significant predictor (Cox P < or =.03). The relative risk of PCSM after CRT for patients with > or = 50% as compared with less than 50% PC was 10.4 (95% CI, 1.2 to 87; Cox P =.03), 6.1 (95% CI, 1.3 to 28.6; Cox P =.02), and 12.5 (95% CI, 1.5 to 107; Cox P =.02) in men with a PSA < or = 10 and Gleason score < or = 6, PSA < or = 10 and Gleason score < or = 7, and PSA < or = 15 and Gleason score < or = 6, respectively. By 5 years after CRT, 5% to 9% compared with less than 1% (log-rank P < or =.01) of these patients experienced PCSM if they had > or = 50% compared with less than 50% PC, respectively.
  
  
  CONCLUSIONS
  CRT dose-escalation techniques, the addition of hormonal therapy, or both should be considered in the management of patients with low or favorable intermediate-risk disease and > or = 50% PC.
authors.affiliation: Department of Radiation Oncology, Brigham and Women's Hospital and Dana-Farber Cancer Institute, Boston, MA 02215, USA. adamico@lroc.harvard.edu
authors.forename: Anthony V
authors.initials: AV
authors.lastname: D'Amico
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Renshaw
authors.forename: Kerri
authors.initials: K
authors.lastname: Cote
authors.forename: Mark
authors.initials: M
authors.lastname: Hurwitz
authors.forename: Clair
authors.initials: C
authors.lastname: Beard
authors.forename: Marian
authors.initials: M
authors.lastname: Loffredo
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001706:Biopsy; D015331:Cohort Studies; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000401:mortality / Q000473:pathology* / Q000532:radiotherapy*; D020266:Radiotherapy, Conformal; D012307:Risk Factors
chemical_list: D018931:Antineoplastic Agents, Hormonal; D017430:Prostate-Specific Antigen