Prospective evaluation of an extended 21-core biopsy scheme as initial prostate cancer diagnostic strategy.
BACKGROUND
The debate on the optimal number of prostate biopsy core samples that should be taken as an initial strategy is open.


OBJECTIVE
To prospectively evaluate the diagnostic yield of a 21-core biopsy protocol as an initial strategy for prostate cancer (PCa) detection.


METHODS
During 10 yr, 2753 consecutive patients underwent a 21-core biopsy scheme for their first set of biopsy specimens.


METHODS
All patients underwent a standardized 21-core protocol with cores mapped for location.


METHODS
The PCa detection rate of each biopsy scheme (6, 12, or 21 cores) was compared using a McNemar test. Predictive factors of the diagnostic yield achieved by a 21-core scheme were studied using logistic regression analyses.


CONCLUSIONS
PCa detection rates using 6 sextant biopsies, 12 cores, and 21 cores were 32.5%, 40.4%, and 43.3%, respectively. The 12-core procedure improved the cancer detection rate by 19.4% (p=0.004), and the 21-biopsy scheme improved the rate by 6.7% overall (p<0.001). The six far lateral cores were the most efficient in terms of detection rate. The diagnostic yield of the 21-core protocol was >10% in prostates with volume >70 ml, in men with a prostate-specific antigen level<4 ng/ml, with a prostate-specific antigen density (PSAD) <0.20 ng/ml per gram. A PSAD <0.20 ng/ml per gram was the strongest independent predictive factor of the diagnostic yield offered by the 21-core scheme (p<0.001). The 21-core protocol significantly increased the rate of PCa eligible for active surveillance (62.5% vs 48.4%; p=0.036) than those detected by a 12-core scheme without statistically increasing the rate of insignificant PCa (p=0.503).


CONCLUSIONS
A 21-core biopsy scheme improves significantly the PCa detection rate compared with a 12-core protocol. We identified a cut-off PSAD (0.20 ng/ml per gram) below which an extended 21-core scheme might be systematically proposed to significantly improve the overall detection rate without increasing the rate of detected insignificant PCa.
INSERM U955 Equipe 7, Departments of Urology and Pathology, CHU Henri Mondor, APHP, Créteil, France. Electronic address: g.ploussard@gmail.com.
Guillaume
G
Ploussard
Nathalie
N
Nicolaiew
Charles
C
Marchand
Stéphane
S
Terry
Francis
F
Vacherot
Dimitri
D
Vordos
Yves
Y
Allory
Claude-Clément
CC
Abbou
Laurent
L
Salomon
Alexandre
A
de la Taille
D000368:Aged; D062005:Biopsy, Large-Core Needle / Q000379:methods* / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000473:pathology*