The Cancer of the Bladder Risk Assessment (COBRA) score accurately predicts cancer-specific survival after radical cystectomy: external validation and lymphovascular invasion assessment value to improve its performance.

The Cancer of the Bladder Risk Assessment (COBRA) score is a predictive tool for estimating Cancer Specific Survival (CSS) after Radical Cystectomy (RC) for urothelial carcinoma. COBRA score variables are: age at RC, Tumor stage and Lymph Node Density (LND). We sought to externally validate the COBRA score and to improve its performance in estimating CSS adding Lymphovascular Invasion (LVI) as a further variable (Modified COBRA score).