External validation of a PCA-3-based nomogram for predicting prostate cancer and high-grade cancer on initial prostate biopsy.

The aim of this study was to externally validate a previously developed PCA3-based nomogram for the prediction of prostate cancer (PCa) and high-grade (intermediate and/or high-grade) prostate cancer (HGPCa) at the time of initial prostate biopsy.

A retrospective review was performed on a cohort of 336 men from a large urban academic medical center. All men had serum PSA <20 ng/ml and underwent initial transrectal ultrasound-guided prostate biopsy with at least 10 cores sampling for suspicious exam and/or elevated PSA. Covariates were collected for the nomogram and included age, ethnicity, family history (FH) of PCa, PSA at diagnosis, PCA3, total prostate volume (TPV), and abnormal finding on digital rectal exam (DRE). These variables were used to test the accuracy (concordance index) and calibration of a previously published PCA3 nomogram.

Biopsy confirms PCa and HGPCa in 51.0% and 30.4% of validation patients, respectively. This differed from the original cohort in that it had significantly more PCa and HGPCA (51% vs. 44%, P = 0.019; and 30.4% vs. 19.1%, P < 0.001). Despite the differences in PCa detection the concordance index was 75% and 77% for overall PCa and HGPCa, respectively. Calibration for overall PCa was good.

This represents the first external validation of a PCA3-based prostate cancer predictive nomogram in a North American population. Prostate © 2016 Wiley Periodicals, Inc.

The Prostate. 2016 May 16 [Epub ahead of print]

Daniel J Greene, Ahmed Elshafei, Yaw A Nyame, Onder Kara, Ercan Malkoc, Tianming Gao, J Stephen Jones

Department of Urology, Cleveland Clinic Foundation, Glickman Urological and Kidney Institute, Cleveland, Ohio., Department of Urology, Cleveland Clinic Foundation, Glickman Urological and Kidney Institute, Cleveland, Ohio., Department of Urology, Cleveland Clinic Foundation, Glickman Urological and Kidney Institute, Cleveland, Ohio., Department of Urology, Cleveland Clinic Foundation, Glickman Urological and Kidney Institute, Cleveland, Ohio., Department of Urology, Cleveland Clinic Foundation, Glickman Urological and Kidney Institute, Cleveland, Ohio., Department of Quantitative Health Sciences, Cleveland Clinic Foundation, Cleveland, Ohio., Department of Urology, Cleveland Clinic Foundation, Glickman Urological and Kidney Institute, Cleveland, Ohio.