Patients with Non-Muscle-Invasive Bladder Cancer Previously Treated with Nephroureterectomy Have a High Risk of Recurrence after Bacillus Calmette-Gurin Intravesical Instillation Therapy

Background: There is a high incidence of intravesical recurrence after transurethral resection of bladder tumor for non-muscle-invasive bladder cancer (NMIBC). Intravesical instillation of bacillus Calmette-Guerin (BCG) is widely used to prevent recurrence and progression. There are two types of NMIBC: primary NMIBC and subsequent NMIBC after radical nephroureterectomy (RNU). We compared the clinical outcomes of BCG intravesical instillation therapy between the two types of NMIBC. Patients and Methods: This study included a total of 357 patients, who received BCG intravesical instillation therapy to prevent recurrence of NMIBC (pTa/pT1) between 1991 and 2019. Among them, 34 patients had subsequent NMIBC after RNU, and the remaining 323 patients had primary NMIBC. This retrospective study analyzed 68 patients extracted by propensity score matching. Survival curves were estimated using the Kaplan-Meier method, and independent prognostic factors for survival were examined by the Cox proportional hazards model. Results: The 3-year recurrence-free survival (RFS) rates in patients with primary NMIBC and subsequent NMIBC after RNU were 70.7% and 54.8%, respectively (p = 0.036). However, there were no significant differences between the two groups in progression-free survival and cancer-specific survival. Multivariate analysis of RFS showed that only a previous history of upper tract urothelial carcinoma was an independent prognostic and predictive factor. Conclusion: Patients with subsequent NMIBC after RNU treated with BCG intravesical instillation therapy have a higher risk of recurrence than those with primary NMIBC. Thus, stringent follow-up is necessary for patients with subsequent NMIBC after RNU.