Prostate Cancer Prevention Trial risk calculator 2.0 for the prediction of low- vs high-grade prostate cancer.

Abstract

OBJECTIVE:

To modify the Prostate Cancer Prevention Trial risk calculator (PCPTRC) to predict low- vs high-grade (Gleason grade≥7) prostate cancer and incorporate percent free-prostate-specific antigen (PSA).

METHODS:

Data from 6664 Prostate Cancer Prevention Trial placebo arm biopsies (5826 individuals), where prostate-specific antigen and digital rectal examination results were available within 1 year before the biopsy and PSA was ≤10 ng/mL, were used to develop a nominal logistic regression model to predict the risk of no vs low-grade (Gleason grade<7) vs high-grade cancer (Gleason grade≥7). Percent free-PSA was incorporated into the model based on likelihood ratio analysis of a San Antonio Biomarkers of Risk cohort. Models were externally validated on 10 Prostate Biopsy Collaborative Group cohorts and 1 Early Detection Research Network reference set.

RESULTS:

Of all the Prostate Cancer Prevention Trial biopsies, 5468 (82.1%) were negative for prostate cancer, 942 (14.1%) detected low-grade, and 254 (3.8%) detected high-grade disease. Significant predictors were (log base 2) PSA (odds ratio for low-grade vs no cancer, 1.29*; high-grade vs no cancer, 2.02*; high-grade vs low-grade cancer, 1.57*), digital rectal examination (0.96, 1.49*, 1.55*, respectively), age (1.02*, 1.05*, 1.03*, respectively), African American race (1.13, 2.83*, 2.51*, respectively), prior biopsy (0.63*, 0.81, 1.27, respectively), and family history (1.31*, 1.25, 0.95, respectively), where * indicates P value<.05. The new PCPTRC 2.0 either with or without percent free-PSA (also significant by the likelihood ratio method) validated well externally.

CONCLUSION:

By differentiating the risk of low- vs high-grade disease on biopsy, PCPTRC 2.0 better enables physician-patient counseling concerning whether to proceed to biopsy.

• Authors: Donna P Ankerst, Josef Hoefler, Sebastian Bock, Phyllis J Goodman, Andrew Vickers, Javier Hernandez, Lori J Sokoll, Martin G Sanda, John T Wei, Robin J Leach, Ian M Thompson
• Journal: Urology (Urology) Vol. 83 Issue 6 Pg. 1362-7 (Jun 2014) ISSN: 1527-9995 [Electronic] United States
• PMID: 24862395 (Publication Type: Comparative Study, Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Prostate-Specific Antigen

Topics

• Aged
• Biopsy, Needle
• Digital Rectal Examination (methods)
• Double-Blind Method
• Follow-Up Studies
• Humans
• Likelihood Functions
• Logistic Models
• Male
• Middle Aged
• Neoplasm Grading
• Neoplasm Invasiveness (pathology)
• Neoplasm Recurrence, Local (epidemiology, pathology)
• Odds Ratio
• Predictive Value of Tests
• Primary Prevention (methods)
• Prostate-Specific Antigen (blood)
• Prostatic Neoplasms (pathology, prevention & control)
• Reproducibility of Results
• Risk Assessment