Prospective evaluation of an extended 21-core biopsy scheme as initial prostate cancer diagnostic strategy - Abstract

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.

DESIGN, SETTING, AND PARTICIPANTS: During 10 yr, 2753 consecutive patients underwent a 21-core biopsy scheme for their first set of biopsy specimens.

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

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: 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.

RESULTS AND LIMITATIONS: 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 >70ml, 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.

Written by:
Ploussard G, Marchand C, Nicolaiew N, Terry S, Vacherot F, Vordos D, Allory Y, Abbou CC, Salomon L, de la Taille A   Are you the author?
INSERM U955 Equipe 7, Departments of Urology and Pathology, CHU Henri Mondor, APHP, Créteil, France

Reference: Eur Urol. 2012 Jun 9
doi: 10.1016/j.eururo.2012.05.049


PubMed Abstract
PMID: 22698576