title: Clinical, biochemical and pathological features of initial and repeat transrectal ultrasonography prostate biopsy positive patients.
abstract: BACKGROUND
  Using sextant biopsy, 16-41% of prostate cancers were diagnosed on repeat biopsy. The objective of the present study was to compare the differences in the clinical, biochemical and pathological features between patients with positive results on initial and repeat biopsies, with an aim to identify factors that can be used to improve the detection rate of transrectal ultrasound (TRUS) biopsy of the prostate.
  
  
  METHODS
  Between February 2000 and April 2001, 222 patients with a mean age of 64 years (range 38-85) underwent TRUS-guided 10-core prostate biopsy for either abnormal prostate specific antigen (PSA) levels (>4 ng/mL) and/or abnormal digital rectal examination (DRE). Of this number, 165 patients underwent their first biopsy, whereas 45 and 12 patients had had one or two previous biopsies, respectively.
  
  
  RESULTS
  Prostate cancer detection rates for the initial biopsy group (n = 165), second biopsy group (n = 45) and third biopsy group (n = 12) were 29.7, 23.0 and 41.7%, respectively. Six patients who had a negative first 10-core biopsy underwent a second 10-core biopsy and one patient (16%) was found to have cancer. Apart from total prostate volume, there were no significant statistical differences between the patient age, mean total PSA, PSA density, PSA-transition zone density, DRE and TRUS findings between the initial and repeat biopsy groups of subjects who had cancer. Those who had cancer detected only on repeat biopsies had larger prostate glands (P = 0.041).
  
  
  CONCLUSIONS
  Patients who had cancer detected only on repeat biopsies had bigger prostate glands, supporting the hypothesis that TRUS sextant biopsy as a technique suffers the error of under-sampling in a bigger prostate.
authors.affiliation: Department of Urology, Singapore General Hospital, Singapore. gurysp@sgh.com.sg
authors.forename: John Shyi Peng
authors.initials: JS
authors.lastname: Yuen
authors.forename: Weber Kam Onn
authors.initials: WK
authors.lastname: Lau
authors.forename: Lay Guat
authors.initials: LG
authors.lastname: Ng
authors.forename: Puay Hoon
authors.initials: PH
authors.lastname: Tan
authors.forename: Lay Wai
authors.initials: LW
authors.lastname: Khin
authors.forename: Christopher Wai Sam
authors.initials: CW
authors.lastname: Cheng
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle / Q000009:adverse effects / Q000379:methods; D015331:Cohort Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000000981:diagnostic imaging* / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011470:Prostatic Hyperplasia / Q000000981:diagnostic imaging / Q000473:pathology; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D012007:Rectum; D014463:Ultrasonography
chemical_list: D017430:Prostate-Specific Antigen