Presence of Concomitant Non-muscle-invasive Bladder Cancer in Chinese Patients with Upper Tract Urothelial Carcinoma: Risk Factors, Characteristics, and Predictive Value

To explore the characteristics, predictive risk factors, and prognostic effect of concomitant non-muscle-invasive bladder cancer (NMIBC) in patients with upper tract urothelial carcinoma (UTUC). We evaluated 727 consecutive UTUC patients treated with radical resection between 2000 and 2012 in a high-volume center of China. Preoperative cystoscopy was performed in all patients. Patients with previous or concomitant total cystectomy were excluded. Overall, 73 patients (10.0 %) had NMIBC. Concomitant NMIBC was associated with previous bladder cancer (p = 0.003), tumor located in ureter (p = 0.008), multifocality (p < 0.001), and preoperative renal insufficiency (p = 0.023). The presence of concomitant NMIBC was predictive for lower tumor stage (p = 0.019), papillary architecture (p = 0.023), and organ-confined disease (pT < 3 and N-, p = 0.006). The median follow-up duration was 57 months. The presence of concomitant NMIBC was a risk factor for bladder recurrence (p < 0.001), and particularly in patients with non-muscle-invasive UTUCs, it affects cancer-specific survival (odds ratio 1.614, p = 0.030) and contralateral recurrence (odds ratio, 1.907, p = 0.016). Most concomitant NMIBC were found at the lateral wall or bladder neck, while most intravesical recurrences occurred near the site of surgery or posterior wall. The most common site for concomitant NMIBC was lateral wall and bladder neck, and previous bladder cancer, tumor located in ureter, tumor multifocality, and preoperative renal insufficiency were risk factors for concomitant NMIBC. The presence of concomitant NMIBC is predictive for relative better pathologic outcomes but higher rate of bladder recurrence, while the effect on postoperative survival was limited with patients early-stage UTUCs. The potential mechanisms need further investigation.