Progression to T1 High Grade (T1HG) from a Lower Stage/Grade is Associated with Poorer Survival Outcomes than Initial Diagnosis with T1HG Bladder Cancer

Background: Several studies have documented a poor prognosis in those patients who were initially diagnosed with non-muscle-invasive bladder cancer (NMBIC) and progressed to muscle-invasive bladder cancer (MIBC) compared with those who initially presented with MIBC. However, studies regarding this issue have not yet been performed in patients with T1 high-grade (T1HG) tumor. We aimed to compare survival outcomes between patients diagnosed as T1HG after initial transurethral resection of the bladder tumor (TUR-BT) and patients who presented with lower stage and/or grade but progressed to T1HG at the time of tumor recurrence. Methods: The study comprised 499 patients who had a diagnosis of T1HG after initial TUR-BT (initial T1HG group) and 62 patients who progressed to T1HG after TUR-BT at the time of tumor recurrence (progressed T1HG group). Progression was defined as recurrence to a higher grade and/or stage than the previous result, while MIBC progression was defined as progression to stage T2 or higher and/or N+, and/or M1. Results: The median overall survival (OS) and cancer-specific survival (CSS) durations were 38.0 and 29.0 months, respectively. Kaplan–Meier curve analysis showed significantly decreased 5-year OS (74.4 vs. 57.4%), CSS (86.4 vs. 72.8%), and MIBC progression-free survival (82.6 vs. 62.2%) in the progressed T1HG group. Multivariate analysis revealed that progressed T1HG was a significant predictor of OS, CSS, and MIBC progression (all, p < 0.05). Conclusions: The progressed T1HG group showed poorer survival outcomes compared with the initial T1HG group. Consequently, in patients who progress to T1HG, intensive surveillance and treatment strategies should be considered.