title: When Should a Positive Surgical Margin Ring a Bell? An Analysis of a Multi-Institutional Robot-Assisted Laparoscopic Radical Prostatectomy Database.
abstract: OBJECTIVE
  The impact of positive surgical margin (SM) on cancer control outcomes in prostate cancer patients is a subject of continuous debate. We test the hypothesis that the impact of SM on clinical recurrence (CR) rate may vary based on the other clinical/pathologic characteristics of the tumor.
  
  
  METHODS
  We focused on 5290 patients treated with robot-assisted radical prostatectomy and pelvic node dissection, between 2002 and 2013, at three tertiary care centers. Regression tree analysis stratified patients into risk groups based on their tumor characteristics and the corresponding CR rate. Kaplan-Meier log-rank and multivariable Cox regression models tested the relationship between SM status and CR rate in each tree-generated risk group.
  
  
  RESULTS
  Mean (median) follow-up time was 47.7 (39.0) months. Regression tree analysis that considered all available covariates, except SM status, divided patients based on their CR risk into the following risk groups: (1) high risk (any pT3b/pT4 disease); (2) intermediate risk (≤pT3a disease and pGS 8-10); (3) low risk (≤pT3a, pGS ≤7, and prostate-specific antigen [PSA] >9 ng/mL); and (4) very low risk (≤pT3a, pGS ≤7, and PSA ≤9 ng/mL). Positive SM had a significant detrimental impact on CR risk only in two groups: intermediate risk (p < 0.001) and high risk (p = 0.01). These observations were confirmed by multivariable analyses.
  
  
  CONCLUSIONS
  Our findings show that positive SM had a detrimental impact on CR only in a minority of patients (15%), specifically in those with advanced pathologic stage and/or pathologically poorly differentiated tumor. For all the remaining patients (85%), positive SM by itself did not increase the risk of CR.
authors.affiliation: 1 Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Health System , Detroit, Michigan.
authors.forename: Firas
authors.initials: F
authors.lastname: Abdollah
authors.affiliation: 2 Department of Urology, Vita Salute San Raffaele University , Milan, Italy .
authors.forename: Marco
authors.initials: M
authors.lastname: Moschini
authors.affiliation: 1 Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Health System , Detroit, Michigan.
authors.forename: Akshay
authors.initials: A
authors.lastname: Sood
authors.affiliation: 1 Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Health System , Detroit, Michigan.
authors.forename: Jesse
authors.initials: J
authors.lastname: Sammon
authors.affiliation: 1 Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Health System , Detroit, Michigan.
authors.forename: Deepansh
authors.initials: D
authors.lastname: Dalela
authors.affiliation: 1 Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Health System , Detroit, Michigan.
authors.forename: Linda
authors.initials: L
authors.lastname: Hsu
authors.affiliation: 3 Martini-Clinic, Prostate Cancer Center, University Medical Center Hamburg-Eppendorf , Hamburg, Germany .
authors.forename: Burkhard
authors.initials: B
authors.lastname: Beyer
authors.affiliation: 3 Martini-Clinic, Prostate Cancer Center, University Medical Center Hamburg-Eppendorf , Hamburg, Germany .
authors.forename: Alexander
authors.initials: A
authors.lastname: Haese
authors.affiliation: 3 Martini-Clinic, Prostate Cancer Center, University Medical Center Hamburg-Eppendorf , Hamburg, Germany .
authors.forename: Markus
authors.initials: M
authors.lastname: Graefen
authors.affiliation: 2 Department of Urology, Vita Salute San Raffaele University , Milan, Italy .
authors.forename: Giorgio
authors.initials: G
authors.lastname: Gandaglia
authors.affiliation: 2 Department of Urology, Vita Salute San Raffaele University , Milan, Italy .
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
authors.affiliation: 2 Department of Urology, Vita Salute San Raffaele University , Milan, Italy .
authors.forename: Alberto
authors.initials: A
authors.lastname: Briganti
authors.affiliation: 1 Vattikuti Urology Institute and VUI Center for Outcomes Research Analytics and Evaluation, Henry Ford Health System , Detroit, Michigan.
authors.forename: Mani
authors.initials: M
authors.lastname: Menon
mesh_terms: D000368:Aged; D017024:Chemotherapy, Adjuvant; D016208:Databases, Factual; D018572:Disease-Free Survival; D006801:Humans; D053208:Kaplan-Meier Estimate; D010535:Laparoscopy; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000453:epidemiology*; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D010388:Pelvis; D016016:Proportional Hazards Models; D017430:Prostate-Specific Antigen / Q000097:blood; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology / Q000601:surgery*; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D012307:Risk Factors; D065287:Robotic Surgical Procedures
chemical_list: D017430:Prostate-Specific Antigen