title: Early radiotherapy after radical prostatectomy improves cancer-specific survival only in patients with highly aggressive prostate cancer: validation of recently released criteria.
abstract: OBJECTIVE
  To test the effect of radiotherapy administered within 6 months after radical prostatectomy on cancer-specific mortality in prostate cancer patients after stratification according to a risk score.
  
  
  METHODS
  Overall, 7616 patients with pT3/4 N0/1 prostate cancer treated with radical prostatectomy between 1995 and 2009 within the Surveillance Epidemiology and End Results Medicare-linked database were included in the study. Competing-risks regression models were carried out to test the effect of early radiotherapy on cancer-specific mortality in the entire cohort, and after stratifying patients according to the risk score based on the number and nature of adverse pathological characteristics (Gleason score 8-10; pT3b/4, lymph node invasion).
  
  
  RESULTS
  The risk score was associated with increasing 5- and 10-year cancer-specific mortality rates (P < 0.001). When considering only patients with a risk score ≥ 2, 5- and 10-year cancer-specific mortality rates were significantly lower for individuals undergoing early radiotherapy compared with their counterparts not receiving early radiotherapy (2.9 and 6.9 vs 5.7 and 16.2%, respectively; P = 0.002). The corresponding number required to treat to prevent one death from prostate cancer at 10-year follow up was 10. Early radiotherapy was not associated with lower cancer-specific mortality rates overall and in patients with a risk score <2. This was confirmed in multivariable analyses, where early radiotherapy decreased the risk of cancer-specific mortality only in patients with a risk score ≥ 2 (P ≤ 0.02).
  
  
  CONCLUSIONS
  The presence of two or more of the following pathological features might be used to identify patients who benefit from early radiotherapy: Gleason score 8-10, pT3b/4 and lymph node invasion.
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Quebec, Canada; Department of Urology, Vita Salute San Raffaele University, Milan, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Gandaglia
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
authors.forename: Alberto
authors.initials: A
authors.lastname: Briganti
authors.forename: Vincent
authors.initials: V
authors.lastname: Trudeau
authors.forename: Quoc-Dien
authors.initials: QD
authors.lastname: Trinh
authors.forename: Simon P
authors.initials: SP
authors.lastname: Kim
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
authors.forename: Paul L
authors.initials: PL
authors.lastname: Nguyen
authors.forename: Firas
authors.initials: F
authors.lastname: Abdollah
authors.forename: Maxine
authors.initials: M
authors.lastname: Sun
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011467:Prostate / Q000473:pathology*; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D015203:Reproducibility of Results; D018570:Risk Assessment; D016019:Survival Analysis
keywords: adjuvant radiotherapy; cancer-specific survival; competing-risks; early radiotherapy; prostate cancer; radical prostatectomy; risk score