Stability of Prognostic Estimation Using the CAPRA Score Incorporating Imaging-based vs Physical Exam-based Staging

Area of Science:

• Urology
• Oncology
• Medical Imaging

Background:

• Official prostate cancer T-staging relies on digital rectal examination (DRE).
• Transrectal ultrasound (TRUS) and MRI are increasingly used for clinical staging to guide management.
• The impact of integrating imaging into T-staging on prognostic instruments needs assessment.

Purpose of the Study:

• To evaluate the effect of incorporating imaging findings (TRUS/MRI) into T-staging on the performance of the Cancer of the Prostate Risk Assessment (CAPRA) score.
• To compare the predictive accuracy of the CAPRA score using DRE-based versus imaging-based T-staging for biochemical recurrence.

Main Methods:

• Retrospective analysis of 2,222 men with prostate cancer undergoing radical prostatectomy (2000-2019).
• CAPRA score calculated using both DRE-based and imaging-based T-staging.
• Cox proportional hazards models used to assess associations with biochemical recurrence.
• Model discrimination and net benefit evaluated using time-dependent AUC and decision curve analysis.

Main Results:

• 17% of patients had an increased CAPRA score with imaging-based staging.
• Both DRE-based and imaging-based CAPRA scores demonstrated comparable accuracy in predicting recurrence.
• Positive DRE and imaging-based clinical T3/4 disease were independently associated with biochemical recurrence.

Conclusions:

• The CAPRA score remains a reliable predictor of biochemical recurrence, whether T-staging is based on DRE or imaging.
• Minor discrepancies exist between DRE-based and imaging-based staging, but overall predictive performance is similar.
• Staging information from either DRE or imaging can be used in CAPRA score calculation with reliable risk prediction.