Prognostic significance of tumor budding in muscle invasive urothelial carcinomas of the urinary bladder.

ABSTRACT

OBJECTIVE: The aim of the present study was to analyze the prognostic significance of tumor budding in muscle-invasive urothelial carcinomas of the urinary bladder, and also to determine an optimal threshold value in evaluation. PATIENTS AND METHODS: The study included 108 patients diagnosed with muscleinvasive conventional urothelial carcinoma between 2010 and 2020. Tumor budding was evaluated on H&E-stained slides. The critical tumor budding number was determined with the "receiver operating characteristics (ROC)" curve. Cases with a tumor budding number of ≤6 were categorized as low, and cases with >6 as high tumor budding. RESULTS: The univariate Cox proportional hazards regression model for recurrence-free survival showed that lymphovascular invasion (P = 0.001), tumor budding (P = 0.012), pT stage (T4 vs. T2) (P = 0.005), and lymph node metastasis (P = 0.009) were significantly associated with recurrence-free survival. The multivariate Cox proportional hazards regression model utilizing backward stepwise (wald) method revealed that only LVI (P = 0.001) was independent risk factor for recurrence-free survival. The univariate Cox analysis showed that lymphovascular invasion (P = 0.001), tumor budding (P = 0.004), pT stage (T4 vs. T2) (P = 0.003), and lymph node metastasis (P = 0.001) were significantly associated with overall survival. The multivariate Cox analysis (backward stepwise (wald) method) revealed that tumor focality (P = 0.018), pT stage (T4 vs. T2) (P = 0.015), and lymphovascular invasion (P = 0.002) were independent factors for overall survival. CONCLUSIONS: Our findings suggested that the evaluation of tumor budding may be a useful parameter for predicting outcome in patients with muscle-invasive bladder cancer.