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Published on: March 21, 2025
Magnetic Resonance Imaging (MRI)-Adapted Prostate Cancer Risk Tool Incorporating Cribriform and Intraductal Carcinoma
Ngoc-Nhu Jennifer Nguyen1, Kristen Liu2, Katherine Lajkosz3
1Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; Department of Anatomic Pathology, Precision Diagnostics and Therapeutics Program, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
A new tool, MAPCaRT (MRI-adapted prostate cancer risk tool), improves risk prediction for prostate cancer by including cribriform carcinoma/intraductal carcinoma (CC/IDC). This enhanced tool offers better guidance for patient management after biopsies.
Area of Science:
- Urology
- Oncology
- Medical Imaging
- Biostatistics
Background:
- Current prostate cancer risk stratification tools lack adaptation for MRI-targeted biopsies.
- These tools do not incorporate cribriform carcinoma/intraductal carcinoma (CC/IDC), a key predictor of adverse outcomes.
- There is a need for improved risk assessment tools that integrate advanced biopsy techniques and histopathological findings.
Purpose of the Study:
- To develop and validate an MRI-adapted prostate cancer risk tool (MAPCaRT).
- To incorporate the presence of CC/IDC into the existing Cancer of the Prostate Risk Assessment (CAPRA) tool.
- To compare the prognostic performance of MAPCaRT against CAPRA in patients undergoing MRI-targeted and systematic biopsies.
Main Methods:
- MAPCaRT was developed by modifying the CAPRA tool to include CC/IDC presence and adapting risk assessment for MRI-targeted biopsies using aggregate core count and radiological stage.
- A Cox proportional hazards model was used to determine point attribution for CC/IDC and Gleason score.
- Model performance was evaluated using Kaplan-Meier curves, Harrell C-indices, and decision curve analysis for biochemical recurrence-free survival (BCR-FS) and event-free survival (EFS) in cohorts with matched radical prostatectomy.
Main Results:
- In the MRI-targeted biopsy cohort (n=266), MAPCaRT showed a significant improvement in the C-index for BCR-FS compared to CAPRA (0.635 vs 0.574, P = .045) and greater net clinical benefit.
- In the systematic biopsy cohort (n=1291), MAPCaRT demonstrated improved C-index for BCR-FS (0.696 vs 0.655, P < .001) and greater net clinical benefit for both BCR-FS and EFS.
- CC/IDC was present in 32% of MRI-targeted biopsies and 23% of systematic biopsies, highlighting its prevalence and importance in risk stratification.
Conclusions:
- MAPCaRT, a modified CAPRA tool incorporating CC/IDC, provides improved prediction of biochemical recurrence-free survival and event-free survival.
- The developed tool (available at prostatecancercalculator.lmp.utoronto.ca) offers enhanced clinical guidance for prostate cancer management decisions.
- MAPCaRT represents a significant advancement in risk stratification for prostate cancer, particularly for patients assessed with MRI-targeted biopsies.
