Comparisons of Novel Risk Stratification Models to the Current cT1a/b Staging in Incidental Prostate Cancer
Lukas Scheipner1,2, Andrea Baudo1,3, Letizia Maria Ippolita Jannello1,4,5
1Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montréal Health Center, Montréal, Québec, Canada.
The Prostate
|August 2, 2026
Summary
Gleason score (GS) stratification, specifically <8 vs. ≥8, significantly improves cancer-specific survival (CSS) predictions for incidental prostate cancer (PCa) compared to current cT1a/cT1b staging. This new model offers better accuracy for predicting patient outcomes.
Area of Science:
- Urology
- Oncology
- Medical Statistics
Background:
- Incidental prostate cancer (PCa) is currently staged as cT1a or cT1b based on tumor volume in resected tissue.
- This traditional staging method may not fully capture variations in cancer-specific survival (CSS).
Purpose of the Study:
- To evaluate alternative stratification models for incidental PCa.
- To identify a model that improves prediction of cancer-specific survival (CSS) beyond current staging methods.
Main Methods:
- Retrospective analysis of 5155 incidental PCa patients from the SEER database (2004-2015).
- Comparison of CSS at 5 years using Kaplan-Meier plots for different stratification models.
- Development and validation of multivariable Cox regression models with AUC quantification via 20-fold cross-validation.
Main Results:
- CSS at 5 years was 98% for cT1a vs. 90% for cT1b (p<0.0001).
- A model combining cT1a/cT1b with Gleason score (GS) showed 99% CSS for cT1a/GS 6 vs. 92% for cT1b/GS ≥7 (p<0.0001).
- Stratification by GS <8 vs. ≥8 yielded 98% CSS vs. 72% CSS (p<0.0001), with the highest AUC of 0.88.
Conclusions:
- Stratification based on Gleason score <8 vs. ≥8 provides superior survival discrimination for incidental PCa.
- This GS-based model demonstrates higher accuracy and is better suited than cT1a/cT1b substaging for predicting CSS.
