Critical assessment of tools to predict clinically insignificant prostate cancer at radical prostatectomy in contemporary men.

Abstract

BACKGROUND:

Overtreatment of prostate cancer (PCa) is a concern, especially in patients who might qualify for the diagnosis of insignificant prostate cancer (IPCa). The ability to identify IPCa prior to definitive therapy was tested.

METHODS:

In a cohort of 1132 men a nomogram was developed to predict the probability of IPCa. Predictors consisted of prostate-specific antigen (PSA), clinical stage, biopsy Gleason sum, core cancer length and percentage of positive biopsy cores (percent positive cores). IPCa was defined as organ-confined PCa (OC) with tumor volume (TV) <0.5 cc and without Gleason 4 or 5 patterns. Finally, an external validation of the most accurate IPCa nomogram was performed in the same group.

RESULTS:

IPCa was pathologically confirmed in 65 (5.7%) men. The 200 bootstrap-corrected predictive accuracy of the new nomogram was 90% versus 81% for the older nomogram. However, in cutoff-based analyses of patients who were qualified by our and the older nomograms as high probability for IPCa, respectively 63% and 45% harbored aggressive PCa variants at radical prostatectomy (Gleason score 7-10, ECE, SVI, and/or LNI).

CONCLUSIONS:

Despite a high accuracy, currently available models for prediction of IPCa are incorrect in 10% to 20% of predictions. The rate of misclassification is even further inflated when specific cutoffs are used. As a consequence, extreme caution is advised when statistical tools are used to assign the diagnosis of IPCa.

• Authors: Felix K-H Chun, Alexander Haese, Sascha A Ahyai, Jochen Walz, Nazareno Suardi, Umberto Capitanio, Markus Graefen, Andreas Erbersdobler, Hartwig Huland, Pierre I Karakiewicz
• Journal: Cancer (Cancer) Vol. 113 Issue 4 Pg. 701-9 (Aug 15 2008) ISSN: 0008-543X [Print] United States
• PMID: 18553365 (Publication Type: Comparative Study, Evaluation Study, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: 2008 American Cancer Society

Chemical References

• Prostate-Specific Antigen

Topics

• Biopsy
• Humans
• Male
• Nomograms
• Predictive Value of Tests
• Prostate-Specific Antigen
• Prostatectomy
• Prostatic Neoplasms (diagnosis, surgery)
• Risk Assessment
• Tumor Burden