title: Is there a role for anterior zone sampling as part of saturation trans-rectal ultrasound guided prostate biopsy?
abstract: BACKGROUND
  The prostatic anterior zone (AZ) is not targeted routinely by TRUS guided prostate biopsy (TRUS-Pbx). MRI is an accurate diagnostic tool for AZ tumors, but is often unavailable due to cost or system restrictions. We examined the diagnostic yield of office based AZ TRUS-Pbx.
  
  
  METHODS
  127 men at risk for AZ tumors were studied: Patients with elevated PSA and previous extended negative TRUS-Pbx (group 1, n = 78) and actively surveyed low risk prostate cancer patients (group 2, n = 49). None of the participants had a previous AZ biopsy. Biopsy template included suspicious ultrasonic areas, 16 peripheral zone (PZ), 4 transitional zone (TZ) and 6 AZ cores. All biopsies were performed by a single urologist under local peri-prostatic anaesthetic, using the B-K Medical US System, an end-firing probe 4-12 MHZ and 18 ga/25 cm needle. All samples were reviewed by a single specialized uro-pathologist. Multivariate analysis was used to detect predictors for AZ tumors accounting for age, PSA, PSA density, prostate volume, BMI, and number of previous biopsies.
  
  
  RESULTS
  Median PSA was 10.4 (group 1) and 7.3 (group 2). Age (63.9, 64.5), number of previous biopsies (1.5) and cores (17.8, 21.3) and prostate volume (56.4 cc, 51 cc) were similar for both groups. The overall diagnostic yield was 34.6% (group 1) and 85.7% (group 2). AZ cancers were detected in 21.8% (group 1) and 34.7% (group 2) but were rarely the only zone involved (1.3% and 4.1% respectively). Gleason ≥ 7 AZ cancers were often accompanied by equal grade PZ tumors. In multivariate analysis only prostate volume predicted for AZ tumors. Patients detected with AZ tumors had significantly smaller prostates (36.9 cc vs. 61.1 cc p < 0.001). Suspicious AZ ultrasonic findings were uncommon (6.3%).
  
  
  CONCLUSIONS
  TRUS-Pbx AZ sampling rarely improves the diagnostic yield of extended PZ sampling in patients with elevated PSA and previous negative biopsies. In low risk prostate cancer patients who are followed by active surveillance, AZ sampling changes risk stratification in 6% but larger studies are needed to define the role of AZ sampling in this population and its correlation with prostatectomy final pathological specimens.
authors.forename: Eric
authors.initials: E
authors.lastname: Cole
authors.forename: David
authors.initials: D
authors.lastname: Margel
authors.forename: Michael
authors.initials: M
authors.lastname: Greenspan
authors.forename: Bobby
authors.initials: B
authors.lastname: Shayegan
authors.forename: Edward
authors.initials: E
authors.lastname: Matsumoto
authors.forename: Marc A
authors.initials: MA
authors.lastname: Fischer
authors.forename: Michael
authors.initials: M
authors.lastname: Patlas
authors.forename: Dean
authors.initials: D
authors.lastname: Daya
authors.affiliation: Department of Surgery Division of Urology, McMaster University, Hamilton, Ontario, Canada. Jehonathan.Pinthus@jcc.hhsc.ca.
authors.forename: Jehonathan H
authors.initials: JH
authors.lastname: Pinthus
mesh_terms: D061765:Endoscopic Ultrasound-Guided Fine Needle Aspiration / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity