title: The optimal rebiopsy prostatic scheme depends on patient clinical characteristics: results of a recursive partitioning analysis based on a 24-core systematic scheme.
abstract: BACKGROUND
  The most beneficial number and the location of prostate biopsies remain matters of debate, especially after an initial negative biopsy.
  
  
  OBJECTIVE
  To identify the optimal combination of sampling sites (number and location) to detect prostate cancer (PCa) in patients previously submitted to an initial negative prostatic biopsy.
  
  
  METHODS
  A transrectal ultrasound-guided systematic 24-core prostate biopsy (24PBx) was performed prospectively in 340 consecutive patients after a first negative biopsy (at least 12 cores).
  
  
  METHODS
  We relied on a classification and regression tree analysis to identify three clinically different subgroups of patients at dissimilar risk of harboring PCa at second biopsy. Subsequently, we set the cancer-positive rate of the 24PBx at 100% and calculated PCa detection rates for 255 possible combinations of sampling sites. We selected the optimal biopsy scheme (defined as the combination of sampling sites that detected 95% of all the cancers with the minimal number of biopsy cores) for each patient subgroup.
  
  
  CONCLUSIONS
  After an initial negative biopsy, cancer was detected at rebiopsy in 95 men (27.9%). At a given number of cores, the cancer detection rates varied significantly according to the different combination of sites considered. Three different PCa risk groups were identified: (1) previous report of atypical small acinar proliferation of the prostate (ASAP), (2) no previous ASAP and ratio of free prostate-specific antigen (fPSA) to total PSA (%fPSA) ≤10%, and (3) no previous ASAP and %fPSA >10%. For patients with previous ASAP or patients with no previous ASAP and %fPSA ≤10%, two schemes with different combinations of 14 cores were most favorable. The optimal sampling in patients with no previous ASAP and %fPSA >10% was a scheme with a combination of 20 cores.
  
  
  CONCLUSIONS
  Both the number and the location of biopsy cores taken affect cancer detection rates in a repeated biopsy setting. We developed an internally validated flowchart to identify the most advantageous set of sampling sites according to patient characteristics.
authors.affiliation: Department of Urology, University Vita-Salute, Scientific Institute San Raffaele, Milan, Italy. scattoni.vincenzo@hsr.it
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Scattoni
authors.forename: Marco
authors.initials: M
authors.lastname: Raber
authors.forename: Umberto
authors.initials: U
authors.lastname: Capitanio
authors.forename: Firas
authors.initials: F
authors.lastname: Abdollah
authors.forename: Marco
authors.initials: M
authors.lastname: Roscigno
authors.forename: Diego
authors.initials: D
authors.lastname: Angiolilli
authors.forename: Carmen
authors.initials: C
authors.lastname: Maccagnano
authors.forename: Andrea
authors.initials: A
authors.lastname: Gallina
authors.forename: Antonio
authors.initials: A
authors.lastname: Saccà
authors.forename: Massimo
authors.initials: M
authors.lastname: Freschi
authors.forename: Claudio
authors.initials: C
authors.lastname: Doglioni
authors.forename: Patrizio
authors.initials: P
authors.lastname: Rigatti
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D000368:Aged; D001707:Biopsy, Needle / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000473:pathology*
chemical_list: D017430:Prostate-Specific Antigen