Incidental prostate cancer (PCa) patients are currently stratified to either cT1a vs. cT1b stage, depending on tumor volume (< 5% vs. > 5%) in the resected tissue. We tested for other models that could improve cancer-specific survival (CSS) predictions.
Incidental (cT1a/cT1b) PCa patients were retrospectively identified within the Surveillance, Epidemiology, and End Results (SEER) database (2004-2015). Kaplan-Meier plots illustrated CSS at 5 years of follow-up. Combination of variables resulted in three distinct stratification models based on cT1a vs. cT1b and Gleason score sum (GS). Multivariable Cox regression models that predicted CSS were used for area under the curve (AUC) quantification after 20-fold cross validation.
We identified a total of 5155 incidental PCa patients. CSS at 5 years was 98% for cT1a vs. 90% for cT1b (p < 0.0001). CSS at 5 years for combination of cT1a and GS 6 patients was 99% vs. 92% for patients with either cT1b or GS ≥ 7 (p < 0.0001). Finally, for patients with GS < 8, CSS at 5 years was 98% vs. 72% for patients with GS ≥ 8 (p < 0.0001). The multivariable adjusted AUC was 0.83 vs. 0.82 vs. 0.88, for each model, respectively.
Of all tested stratification models, the consideration of GS stratified between < 8 and ≥ 8 resulted in the best survival discrimination, as well as highest accuracy after cross-validation. In consequence, the use of this model (GS < 8 vs. ≥ 8) appears better suited than the standard cT1a vs. cT1b substaging, when CSS represents the endpoint of interest.
The Prostate. 2026 Aug 02 [Epub ahead of print]
Lukas Scheipner, Andrea Baudo, Letizia Maria Ippolita Jannello, Carolin Siech, Mario de Angelis, Francesco Di Bello, Zhe Tian, Fred Saad, Shahrokh F Shariat, Alberto Briganti, Felix K H Chun, Luca Carmignani, Ottavio De Cobelli, Nicola Longo, Johannes Mischinger, Sascha Ahyai, Pierre I Karakiewicz
Cancer Prognostics and Health Outcomes Unit, Division of Urology, University of Montréal Health Center, Montréal, Québec, Canada., Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples "Federico II", Naples., Medical University of Vienna, Vienna, Austria., Department of Urology, Urological Research Institute, IRCCS San Raffaele Scientific Institute, Comprehensive Cancer Center, Milan, Italy., Università degli Studi di Milano, Milan, Italy., Department of Urology, IEO European Institute of Oncology, IRCCS, Milan, Italy., Department of Urology, Medical University of Graz, Graz, Austria.