title: No residual cancer on radical prostatectomy after positive 10-core biopsy: incidence, biopsy findings, and DNA specimen identity analysis.
abstract: BACKGROUND
  It is uncertain whether extensive prostate-specific antigen (PSA) testing and extended biopsies currently performed will increase the incidence of no residual cancer on subsequent prostatectomy.
  
  
  OBJECTIVE
  To identify the incidence of cases with no residual cancer on prostatectomy after a positive 10-core biopsy and to review the clinical, biopsy, and prostatectomy findings and the results of specimen identity analysis.
  
  
  METHODS
  We identified 9 patients with no residual cancer in 1351 consecutive prostatectomies and we reviewed the clinical, biopsy, and prostatectomy data from our institutional database. In 6 cases encountered after 2003, we also performed a polymerase chain reaction-based microsatellite analysis on formalin-fixed tissue to confirm the identity of the biopsies and prostatectomies.
  
  
  RESULTS
  All patients had positive biopsies in 1 or 2 cores: 1 in 7 and 2 in 2 patients (1 each, unilateral and bilateral). Mean total cancer length on biopsy measured 2.5 mm, which represented 1.7% of the total biopsy tissue. Gleason score 6 was found in 8 of 9 patients and 1 patient had Gleason score 9. Patients' age was 60.3 years, preoperative PSA was 6.0 ng/mL, and PSA density was 0.1 (all means). In 6 cases tested for microsatellite identity, the patient identity was confirmed.
  
  
  CONCLUSIONS
  Incidence of no residual cancer on prostatectomy of 0.67% after 10-core positive biopsy is higher than previously reported. In most cases, finding no residual cancer on prostatectomy after exhaustive work-up may indicate minimal patient disease. Microsatellite analysis provides a useful and cost-effective test in establishing specimen identity.
authors.affiliation: Department of Pathology and Laboratory Medicine, Anatomical Pathology, Rockyview General Hospital, University of Calgary, Calgary, Alberta, Canada. kiril.trpkov@cls.ab.ca
authors.forename: Kiril
authors.initials: K
authors.lastname: Trpkov
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.forename: Robert
authors.initials: R
authors.lastname: Hay
authors.forename: Asli
authors.initials: A
authors.lastname: Yimaz
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D000368:Aged; D001706:Biopsy; D004273:DNA, Neoplasm / Q000032:analysis; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000473:pathology / Q000601:surgery; D010355:Patient Identification Systems; D016133:Polymerase Chain Reaction; D011183:Postoperative Complications / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000235:genetics / Q000473:pathology / Q000601:surgery*; D013048:Specimen Handling
chemical_list: D004273:DNA, Neoplasm