title: Margin involvement at prostatectomy for clinically localized prostate cancer: does a low-risk group exist?
abstract: OBJECTIVE
  To determine whether additional pathology details may provide risk stratification for patients with involved surgical margins at radical prostatectomy (RP).
  
  
  METHODS
  Eligible patients underwent RP between 2003 and 2010. Patients with preoperative prostate-specific antigen (PSA) ≥20, follow-up <12 months, lymph node or seminal vesicle involvement, or who received radiation therapy or hormone therapy prior to PSA relapse were excluded. Surgical specimens were reviewed by a study pathologist, blinded to outcomes. Survival analysis methods were employed to assess disease control and survival rates, as well as association of patient-, tumor-, and treatment-specific factors for endpoints.
  
  
  RESULTS
  Of 355 RP cases, 279 patients were eligible for the present analysis. At a median follow-up of 53 months (range, 16-127), 31/114 (27%) of patients with involved surgical margins experienced PSA relapse, as compared with 7/165 (4%) for negative margins (hazard ratio, 4.997; 95% confidence interval, 2.425-10.296; P < .0001). Detailed pathology review demonstrated associations between PSA relapse and Gleason score at RP, extent of margin involvement (width), capsule penetration, and perineural invasion. Subgroup analysis identified low risk (4%) of 5-year PSA relapse for patients with Gleason ≤6 mm and margin width ≤4 mm (single maximal or cumulative). All subgroups with higher Gleason score or wider margin were associated with >20% risk of PSA relapse at 5 years.
  
  
  CONCLUSIONS
  Within the present study, Gleason score, 6 patients with margin width ≤4 mm appear to have low rates of early PSA relapse following RP. Low-grade cases with larger extent of margin involvement or higher risk Gleason score patients with any margin involvement have high rates of early PSA relapse.
authors.affiliation: Department of Radiation Oncology, Carver School of Medicine, University of Iowa, Iowa City, Iowa; Bismarck Cancer Center, Bismarck, North Dakota. Electronic address: john.m.watkins.md@hotmail.com.
authors.forename: John M
authors.initials: JM
authors.lastname: Watkins
authors.affiliation: Department of Pathology, St. Alexius Medical Center, Bismarck, North Dakota.
authors.forename: Michael
authors.initials: M
authors.lastname: Laszewski
authors.affiliation: Bismarck Cancer Center, Bismarck, North Dakota; Department of Pediatrics, Carver School of Medicine, University of Iowa, Iowa City, Iowa.
authors.forename: Patricia L
authors.initials: PL
authors.lastname: Watkins
authors.affiliation: Bismarck Cancer Center, Bismarck, North Dakota.
authors.forename: Tarek A
authors.initials: TA
authors.lastname: Dufan
authors.affiliation: Department of Urology, Prairie Lakes Specialty Clinic, Watertown, South Dakota.
authors.forename: Christopher
authors.initials: C
authors.lastname: Adducci
mesh_terms: D000328:Adult; D000368:Aged; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery*; D012189:Retrospective Studies; D016019:Survival Analysis; D015996:Survival Rate