Development and validation of a nomogram for predicting prostatic urethral involvement in bladder cancer

Area of Science:

• Urology
• Oncology
• Medical Statistics

Background:

• Prostatic urethral involvement (PUI) in bladder cancer can lead to understaging and affect treatment decisions.
• Identifying predictive factors for PUI is crucial for accurate risk stratification and personalized patient management.

Purpose of the Study:

• To identify independent risk factors associated with PUI in bladder cancer.
• To develop and validate a predictive nomogram model for PUI risk in bladder cancer patients.

Main Methods:

• Retrospective analysis of 295 male patients with bladder urothelial carcinoma undergoing transurethral prostatic biopsy.
• Univariate and multivariate logistic regression analyses to identify risk factors.
• Nomogram construction and internal validation using leave-one-out cross-validation (LOOCV), calibration curves, and decision curve analysis (DCA).

Main Results:

• Multivariate analysis identified tumor multiplicity, trigonal/neck tumor location, high-grade tumors, and recurrent carcinoma as independent risk factors for PUI (all P < 0.05).
• The developed nomogram demonstrated strong discrimination (AUC = 0.8) and excellent calibration, with consistent results in non-muscle-invasive bladder cancer (NMIBC) subgroup analysis (AUC = 0.819).
• Decision curve analysis confirmed the clinical utility of the nomogram across various risk thresholds.

Conclusions:

• The established nomogram is a robust tool for stratifying PUI risk in bladder cancer patients.
• This predictive model can guide selective prostatic biopsies and inform personalized treatment strategies.
• Integration into clinical workflows may improve staging accuracy and optimize patient outcomes, though external validation is recommended.