Introduction:

Outcomes of non-muscle invasive bladder cancer (NMIBC) patients managed with intravesical treatments (IVT), including BCG, are well described in high-risk NMIBC cohorts. The use of IVT in a strictly low-grade (LG) patient population is not well characterized. In the era of BCG shortage, current guidelines recommend reserving BCG for treatment of higher risk disease. However, use of IVT can be considered in select patients with LG NMIBC. Here, we aim to characterize practice patterns and outcomes of LG NMIBC patients managed with IVT.

Methods:

Following IRB approval, a retrospective analysis of patients presenting with LG NMIBC to Moffitt Cancer Center between 1/18/2017 and 10/9/2023 was performed. Patients with incomplete treatment data, mixed-grade pathology, non-LG pathology at index cancer diagnosis, and follow-up less than 12 month were excluded. Clinicopathologic data was abstracted for each patient including demographics, histopathological features, and treatment history. Recurrence-free survival (RFS) and progression-free survival (PFS) were computed using Kaplan-Meier (KM) analysis. Survival estimates were compared using the log-rank test to determine statistical significance between treatment groups.

Results:

Of the 450 patients queried, 131 met study criteria and were included. The study population is predominantly white (95.8%), male (69.3%), and with a median age of 67 years (IQR 15.0). At a median follow-up of 41.7 months (IQR 32.7), 31.3% of patients remained recurrence-free, 68.7% experience at least one tumor recurrence, and 16.6% experienced progression to higher grade/stage disease. Following initial diagnosis, 41 (31.8%) received IVT up front, with the most used agent being BCG (61%), followed by Gemcitabine and Mitomycin C (19.5% and 17.1%, respectively, Figure 1). Patients who received IVT following initial diagnosis experienced statistically significant improvement in RFS (p = 0.015, Figure 2). When stratified by type of IVT given, only those who received BCG experienced statistically significant improvements in RFS as compared to those who received non-BCG IVTs (p = 0.026). There were no differences in PFS (p = 0.49).

Conclusion:

In this select cohort of patients presenting with purely LG NMIBC, a notable portion received up front induction IVT following initial resection. BCG is the most employed agent, and its use is associated with statistical, albeit modest improvement in RFS.  Given the overall excellent prognosis and low risk of progression, the marginal benefit of induction BCG in patients with index LG NMIBC needs to be considered in the context of current BCG shortage. Additionally, our study showed that non-BCG IVT did not impact cancer recurrence or progression, suggesting limited value in this clinical setting. Validation of the above findings in a larger cohort will further our understanding of the clinical utility of IVT in low- and intermediate-risk NMIBC.  

Funding: N/A