title: Prediction of outcome following early salvage radiotherapy among patients with biochemical recurrence after radical prostatectomy.
abstract: BACKGROUND
  Early salvage radiotherapy (eSRT) represents the only curative option for prostate cancer patients experiencing biochemical recurrence (BCR) for local recurrence after radical prostatectomy (RP).
  
  
  OBJECTIVE
  To develop and internally validate a novel nomogram predicting BCR after eSRT in patients treated with RP.
  
  
  METHODS
  Using a multi-institutional cohort, 472 node-negative patients who experienced BCR after RP were identified. All patients received eSRT, defined as local radiation to the prostate and seminal vesicle bed, delivered at prostate-specific antigen (PSA) ≤ 0.5 ng/ml.
  
  
  METHODS
  BCR after eSRT was defined as two consecutive PSA values ≥ 0.2 ng/ml. Uni- and multivariable Cox regression models predicting BCR after eSRT were fitted. Regression-based coefficients were used to develop a nomogram predicting the risk of 5-yr BCR after eSRT. The discrimination of the nomogram was quantified with the Harrell concordance index and the calibration plot method. Two hundred bootstrap resamples were used for internal validation.
  
  
  CONCLUSIONS
  Mean follow-up was 58 mo (median: 48 mo). Overall, 5-yr BCR-free survival rate after eSRT was 73.4%. In univariable analyses, pathologic stage, Gleason score, and positive surgical margins were associated with the risk of BCR after eSRT (all p ≤ 0.04). These results were confirmed in multivariable analysis, where all the previously mentioned covariates as well as pre-RT PSA were significantly associated with BCR after eSRT (all p ≤ 0.04). A coefficient-based nomogram demonstrated a bootstrap-corrected discrimination of 0.74. Our study is limited by its retrospective nature and use of BCR as an end point.
  
  
  CONCLUSIONS
  eSRT leads to excellent cancer control in patients with BCR for presumed local failure after RP. We developed the first nomogram to predict outcome after eSRT. Our model facilitates risk stratification and patient counselling regarding the use of secondary therapy for individuals experiencing BCR after RP.
  
  
  RESULTS
  Salvage radiotherapy leads to optimal cancer control in patients who experience recurrence after radical prostatectomy. We developed a novel tool to identify the best candidates for salvage treatment and to allow selection of patients to be considered for additional forms of therapy.
authors.affiliation: Department of Urology, Vita-Salute University, San Raffaele Scientific Institute, Milan, Italy. Electronic address: briganti.alberto@hsr.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Briganti
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN, USA.
authors.forename: R Jeffrey
authors.initials: RJ
authors.lastname: Karnes
authors.affiliation: University Hospitals Leuven, Department of Urology, Leuven, Belgium.
authors.forename: Steven
authors.initials: S
authors.lastname: Joniau
authors.affiliation: Department of Urology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Boorjian
authors.affiliation: Department of Radiotherapy, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Cozzarini
authors.affiliation: Department of Urology, Vita-Salute University, San Raffaele Scientific Institute, Milan, Italy; Cancer Prognostics and Health Outcomes Unit, University of Montreal, Montreal, Canada.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Gandaglia
authors.affiliation: Department of Radiation Oncology, Charité Universitätsmedizin, Campus Benjamin Franklin, Berlin, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Hinkelbein
authors.affiliation: University Hospitals Leuven, Department of Radiotherapy, Leuven, Belgium.
authors.forename: Karin
authors.initials: K
authors.lastname: Haustermans
authors.affiliation: Department of Urology, Université Catholique de Louvain, Brussels, Belgium.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Tombal
authors.affiliation: Department of Urology, Medical University of Vienna, Vienna, Austria.
authors.forename: Shahrokh
authors.initials: S
authors.lastname: Shariat
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal, Montreal, Canada.
authors.forename: Maxine
authors.initials: M
authors.lastname: Sun
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal, Montreal, Canada.
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
authors.affiliation: Department of Urology, Vita-Salute University, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
authors.affiliation: University Hospitals Leuven, Department of Urology, Leuven, Belgium.
authors.forename: Hein
authors.initials: H
authors.lastname: Van Poppel
authors.affiliation: Department of Radiation Oncology, University Hospital Ulm, Ulm, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wiegel
mesh_terms: D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000473:pathology* / Q000532:radiotherapy*; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D049451:Nomograms; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology* / Q000628:therapy*; D012189:Retrospective Studies; D016879:Salvage Therapy; D015996:Survival Rate
chemical_list: D017430:Prostate-Specific Antigen
keywords: Biochemical recurrence; Nomogram; Prostate cancer; Radical prostatectomy; Salvage radiotherapy