title: Analysis of the Cancer of the Prostate Risk Assessment to predict for biochemical failure after external beam radiotherapy or prostate seed brachytherapy.
abstract: OBJECTIVE
  To analyze the value of the Cancer of the Prostate Risk Assessment (CAPRA) score to predict biochemical failure (bF) in patients with D'Amico low- or intermediate-risk prostate cancer treated with different radiation techniques.
  
  
  METHODS
  We analyzed 744 patients treated with either external beam radiotherapy (52.7%) or permanent-seed prostate brachytherapy (47.3%) without any androgen deprivation. External beam radiotherapy dose levels were extreme hypofractionation (45 Gy in 9 fractions) in 10%, 76-79.2 Gy (in 1.8-2.0 Gy per fraction) in 32.7%, and 70.2-74 Gy in 10%. All patients had a minimum of 36-month follow-up. Cox regression analysis was used for univariate and multivariate analysis to predict for bF, as per the Phoenix definition (prostate-specific antigen-nadir + 2 ng/mL).
  
  
  RESULTS
  Median follow-up for patients without bF was 56 months (range, 36-114 months). In univariate analysis, CAPRA score as a continuous variable was predictive of bF (hazard ratio [HR], 1.49; 95% confidence interval [CI], 1.23-1.79; P <.001), and in multivariate analysis adjusted for treatment type, the HR was 1.39 (95% CI, 1.14-1.71; P = .002). D'Amico intermediate-risk vs low-risk patients had an HR for bF of 1.93 (95% CI, 1.07-3.47; P = .029) in univariate analysis, but the difference was not statistically significant anymore after adjustment for treatment type, (P = .206). The area under the curve of the CAPRA score as a continuous variable at 3 and 5 years was 0.66 and 0.62, respectively (P = .005 for both years).
  
  
  CONCLUSIONS
  The CAPRA score is predictive of bF. Each 1-point rise increased the risk of bF by 39%, which is comparable to surgical series.
authors.affiliation: Department of Radiation Oncology, Hôpital Notre-Dame, Center Hospitalier de l'Université de Montréal (CHUM), Montreal, Canada; University of Montreal Hospital Research Centre, Montreal, Canada.
authors.forename: Guila
authors.initials: G
authors.lastname: Delouya
authors.affiliation: Department of Radiation Oncology, Hôpital Notre-Dame, Center Hospitalier de l'Université de Montréal (CHUM), Montreal, Canada.
authors.forename: Vimal
authors.initials: V
authors.lastname: Krishnan
authors.affiliation: Department of Radiation Oncology, Hôpital Notre-Dame, Center Hospitalier de l'Université de Montréal (CHUM), Montreal, Canada; University of Montreal Hospital Research Centre, Montreal, Canada.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Bahary
authors.affiliation: University of Montreal Hospital Research Centre, Montreal, Canada.
authors.forename: Sandra
authors.initials: S
authors.lastname: Larrivée
authors.affiliation: Department of Radiation Oncology, Hôpital Notre-Dame, Center Hospitalier de l'Université de Montréal (CHUM), Montreal, Canada; University of Montreal Hospital Research Centre, Montreal, Canada. Electronic address: daniel.taussky.chum@ssss.gouv.qc.ca.
authors.forename: Daniel
authors.initials: D
authors.lastname: Taussky
mesh_terms: D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000532:radiotherapy*; D012189:Retrospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome
chemical_list: D017430:Prostate-Specific Antigen