The first 2 authors contributed equally to this work.
Critical assessment of tools to predict clinically insignificant prostate cancer at radical prostatectomy in contemporary men
Article first published online: 13 JUN 2008
Copyright © 2008 American Cancer Society
Volume 113, Issue 4, pages 701–709, 15 August 2008
How to Cite
Chun, F. K.-H., Haese, A., Ahyai, S. A., Walz, J., Suardi, N., Capitanio, U., Graefen, M., Erbersdobler, A., Huland, H. and Karakiewicz, P. I. (2008), Critical assessment of tools to predict clinically insignificant prostate cancer at radical prostatectomy in contemporary men. Cancer, 113: 701–709. doi: 10.1002/cncr.23610
- Issue published online: 1 AUG 2008
- Article first published online: 13 JUN 2008
- Manuscript Accepted: 7 APR 2008
- Manuscript Revised: 3 APR 2008
- Manuscript Received: 26 FEB 2008
- University of Montreal Health Center Urology Associated
- Fonds de la Recherche en Santé du Québec
- University of Montreal Department of Surgery
- University of Montreal Health Center (CHUM) Foundation
- “Vereinigung Norddeutscher Urologen (VNU)”
- clinically insignificant prostate cancer;
- clinically meaningful prostate cancer;
- tumor volume;
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.
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.
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).
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. Cancer 2008. © 2008 American Cancer Society.