Bacillus Calmette-Guerin (BCG) therapy is safe and effective in non-muscle invasive bladder cancer (NMIBC) patients with immunomodulating conditions.

INTRODUCTION

Bacillus Calmette-Guerin (BCG) is the most effective therapy available to treat high-risk nonmuscle invasive bladder cancer (NMIBC) patients. However, for patients with immunomodulating conditions BCG is a relative contraindication due to efficacy and safety concerns. To our knowledge, no population-level study evaluating the efficacy and safety profile of BCG for immunomodulated patients exists.

METHODS

NMIBC patients aged 66 years or older were identified in the Surveillance, Epidemiology, and End Results (SEER) - Medicare database from 1975-2013. All patients completed adequate BCG (at least 5 plus 2 treatments completed within 12 months of diagnosis). Two groups were defined: an immunomodulated population identified by immunomodulating conditions such as solid-organ transplantation, HIV, and autoimmune conditions, and an immunocompetent group. The primary endpoint was 5-year progression-free survival defined as progression to systemic chemotherapy, checkpoint inhibitors, radical or partial cystectomy, metastasis, or cancer-specific death. A safety analysis was performed as a secondary outcome.

RESULTS

In a total of 4,277 patients with NMIBC who completed adequate BCG, 606 (14.2%) were immunomodulated. The immunomodulated group was older at diagnosis (P < 0.001), more likely to be female (P < 0.001), more likely to live in a metropolitan area (P < 0.001), and had higher Charlson comorbidity scores (P < 0.001). There were no differences in progression to chemotherapy (P = 0.17), checkpoint inhibitors (P > 0.99), radical cystectomy (P = 0.40), partial cystectomy (P = 0.93), metastasis (P = 0.19), cancer-specific death (P = 0.18) or 5-year total bladder cancer progression (P = 0.30) between the groups. For the safety analysis, rates of disseminated BCG were similar between immunomodulated and immunocompetent patients (0.7% vs. <1.8%, P = 0.51). On multivariable analysis 5-year total bladder cancer progression (HR 1.07 [CI 0.88-1.30]) was similar between the groups.

CONCLUSION

Rates of bladder cancer progression and disseminated BCG complications 5-years after BCG therapy were similar regardless of immunomodulation status. These findings suggest that BCG intravesical therapy can be offered to immunomodulated patients with high-risk NMIBC although theoretical infectious complication risks remain.