Upstaging after Transurethral Resection of the Bladder for Non-Muscle-Invasive Cancer of the Bladder: Who Is at Highest Risk?

Introduction: Transurethral resection of the bladder (TUR-BT) is the standard initial treatment and diagnosis of bladder cancer (BC). Of note, upstaging into muscle-invasive disease (MIBC) during re-resection occurs in a significant proportion of patients. This study aimed to define risk factors at initial TUR-BT for upstaging.

Methods: TUR-BT between 2009 and 2021 were retrospectively screened (n = 3,237). We included patients with visible tumors that received their primary and re-TUR-BT at our institution. Upstaging was defined as pathological tumor stage progression into MIBC at re-TUR-BT. Clinicopathological variables were analyzed for the impact on upstaging.

Results: Two hundred and sixty-six patients/532 TUR-BTs were included in the final analysis. Upstaging occurred in 7.9% (21/266) patients. Patients with upstaging presented with stroma-invasive and papillary non-muscle-invasive BC at primary resection in 85.7% (18/21) and 14.3% (3/21), respectively. Detrusor muscle at primary TUR-BT was significantly less present in patients with upstaging (4.1 vs. 95.9%; p < 0.001). After multivariate analysis, solid tumor configuration (HR: 4.17; 95% CI: 1.23-14.15; p = 0.022) and missing detrusor muscle at initial TUR-BT (HR: 3.58; 95% CI: 1.05-12.24; p = 0.043) were significant risk factors for upstaging into MIBC.

Conclusions: The current study defined two major risk factors for upstaging: missing detrusor muscle and solid tumor configuration. We propose that a second resection should be performed earlier if these risk factors apply.