title: Minimum 6 mm core length is strongly predictive for the presence of glandular tissue in transrectal prostate biopsy.
abstract: BACKGROUND
  Prostate biopsy guidelines recommend that a prostate biopsy not containing glandular prostate tissue should be reported as inadequate. In the literature, there is a lack of any study that addresses the relationship between the length of biopsy cores and the absence of glandular prostate tissue. In this study, we aimed to determine whether a relationship exists between these parameters.
  
  
  METHODS
  We retrospectively evaluated 1,712 consecutive initial transrectal 12-core prostate biopsies. Individual cores were histologically categorized as glandular (benign or malignant) and non-glandular (rectal mucosa, periprostatic adipose tissue, prostatic or periprostatic fibromuscular tissue). Total number of evaluable cores ≤9, highly fragmented, incorrectly numbered or dried biopsies, patients with 5-α reductase inhibitory treatment were excluded.
  
  
  RESULTS
  We analyzed remaining 1,584 patients; 41.7 % had adenocarcinoma. A total of 19,144 cores were sampled. Non-glandular cores were found significantly shorter than glandular cores (p < 0.0001). The percentages of non-glandular cores were significantly higher at the base, apex and lateral biopsy sites (p < 0.0001). We found a 6-mm cutoff value for accurate prediction of glandular sampling with 80.2 % sensitivity and 78.7 % specificity. The risk of non-glandular sampling increased 15-fold in cores ≤6 mm (OR 14.91, 95% CI 13.20-16.83, p < 0.0001).
  
  
  CONCLUSIONS
  Non-glandular sampling was directly associated with shorter core lengths. They were found significantly higher at the base, apex and lateral localizations. We found a 6-mm cutoff value for the prediction of non-glandular samples before the histologic evaluation. Below this value, the risk of non-glandular sampling increased 15-fold. We suggest it for prompt additional sampling during biopsy procedure.
authors.affiliation: Department of Urology, School of Medicine, University of Kocaeli, Kocaeli, Turkey.
authors.forename: Hasan
authors.initials: H
authors.lastname: Yilmaz
authors.affiliation: Department of Urology, School of Medicine, University of Kocaeli, Kocaeli, Turkey. seyfettinciftci@yahoo.com.
authors.forename: Seyfettin
authors.initials: S
authors.lastname: Ciftci
authors.affiliation: Department of Urology, School of Medicine, University of Kocaeli, Kocaeli, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Ustuner
authors.affiliation: Department of Urology, School of Medicine, University of Kocaeli, Kocaeli, Turkey.
authors.forename: Ufuk
authors.initials: U
authors.lastname: Yavuz
authors.affiliation: Department of Urology, Izmit Konak Hospital, Kocaeli, Turkey.
authors.forename: Ali
authors.initials: A
authors.lastname: Saribacak
authors.affiliation: Department of Pathology, School of Medicine, University of Kocaeli, Kocaeli, Turkey.
authors.forename: Bahar
authors.initials: B
authors.lastname: Muezzinoglu
authors.affiliation: Department of Urology, School of Medicine, University of Kocaeli, Kocaeli, Turkey.
authors.forename: Ozdal
authors.initials: O
authors.lastname: Dillioglugil
mesh_terms: D000368:Aged; D062005:Biopsy, Large-Core Needle / Q000295:instrumentation*; D019160:Endosonography / Q000379:methods*; D004867:Equipment Design; D005500:Follow-Up Studies; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D012372:ROC Curve; D012007:Rectum; D012189:Retrospective Studies
keywords: Core length; Prostate biopsy; Prostate cancer