title: [Transrectal biopsy scheme can predict incorrect histological grading in prostate cancer].
abstract: OBJECTIVE
  To identify factors that might explain why a prostate with a Gleason score (GS) <7 in the biopsy specimen can turn out to have a GS ≥7 in the surgical specimen.
  
  
  METHODS
  We compared the GS of biopsy specimens with the GS of surgical specimens in 185 patients who underwent surgery for prostate cancer. We calculated the sensitivity, specificity, and predictive values for the GS of the biopsy specimens. We used Cohen's kappa to determine the degree of concordance between a GS of <7 and ≥7 for the biopsy specimen and the surgical specimen. Age, a family history of prostate cancer, total prostate-specific antigen (tPSA), digital rectal examination, prostate structure and volume, and the number of biopsy cores (biopsy scheme) were analyzed using multivariable logistic regression.
  
  
  RESULTS
  Histological study of biopsy specimens yielded high sensitivity (98%) but low specificity (49%) for GS ≤6 and low sensitivity (35, 26%) and high specificity (93, 99%) for GS=7 and GS ≥7, respectively. Cohen's kappa for the GS from the biopsy and surgical specimens was 0.43 (95% CI=30-56%). The biopsy scheme was the only predictor of discordance in the GS between the two techniques. Among the other variables included in the model, only tPSA showed a slightly significant association. Taking a scheme with less than 7 cores as a reference, we found no difference with 8 to 9 cores but we did find a difference with 10 to 11 cores and with 12 or more cores, with a prevalence ratio of 0.138 (95% CI=0.030-0.513) and 0.277 (95% CI=0.091-0.806), respectively.
  
  
  CONCLUSIONS
  The GS of the biopsy depends on the scheme. This factor must be taken into account when choosing a treatment option in patients with low tumor grade in biopsy specimens.
authors.affiliation: Servicio de Radiodiagnóstico, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Islas Canarias, España. Electronic address: luisaradazul@yahoo.es.
authors.forename: M L
authors.initials: ML
authors.lastname: Nieto-Morales
authors.affiliation: Servicio de Radiodiagnóstico, Hospital Universitario de Canarias, La Laguna, Santa Cruz de Tenerife, Islas Canarias, España.
authors.forename: J
authors.initials: J
authors.lastname: Fernández-Ramos
authors.affiliation: Enfermedades Respiratorias CIBER, Instituto Carlos III, Madrid, España; Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Islas Canarias, España.
authors.forename: L
authors.initials: L
authors.lastname: Pérez-Méndez
authors.affiliation: Servicio de Radiodiagnóstico, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Islas Canarias, España.
authors.forename: E
authors.initials: E
authors.lastname: Alventosa-Fernández
authors.affiliation: Servicio de Radiodiagnóstico, Hospital Universitario de Canarias, La Laguna, Santa Cruz de Tenerife, Islas Canarias, España.
authors.forename: M S
authors.initials: MS
authors.lastname: Pastor-Santoveña
authors.affiliation: Unidad de Investigación, Hospital Universitario Nuestra Señora de Candelaria, Santa Cruz de Tenerife, Islas Canarias, España.
authors.forename: A
authors.initials: A
authors.lastname: Aguirre-Jaime
mesh_terms: D000328:Adult; D000368:Aged; D001707:Biopsy, Needle / Q000379:methods; D003951:Diagnostic Errors; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011237:Predictive Value of Tests; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology*; D012007:Rectum; D012189:Retrospective Studies