Little is known about the impact of prior prostate radiation therapy (RT) on the Bacille Calmette-Guerin (BCG) immunotherapy response in patients with non-muscle invasive bladder cancer (NMIBC).
We hypothesized that the damaging radiation effects on the bladder could negatively influence BCG efficacy.
Men with a history of high-risk NMIBC were identified within the Surveillance, Epidemiology, and End Results-Medicare database. All patients completed adequate BCG defined as at least 5 plus 2 treatments completed within 12 months. Patients were stratified into 2 groups: with prior RT for prostate cancer and without prior RT before the diagnosis of NMIBC. The primary endpoint was a 5-year composite for progression defined as disease progression requiring systemic chemotherapy, checkpoint inhibitors, radical or partial cystectomy, or cancer-specific death.
We identified 3,466 patients with NMIBC, including 145 with prior RT for prostate cancer. Five-year progression occurred in 471 patients (13.6%). Patients with prior RT were older than patients without prior RT (77.0 vs 75.0 years; P < .001). The distribution of T stage was significantly different at diagnosis between the RT and non-RT groups (RT: Ta, 44.8%; Tis, 18.6%; T1, 36.6%; without RT: Ta, 40.9%; Tis, 10.8%; T1, 48.3%; P = .002). No difference in the risk of total progression was observed between patients with and without prior RT (P = .67). Similarly, no difference was observed after multivariable adjustment (hazard ratio, 0.99; 95% CI, 0.61-1.58; P = .95).
For patients with NMIBC who undergo adequate BCG treatment, prior RT for prostate cancer was not associated with worse 5-year progression-free survival.
Bladder cancer (Amsterdam, Netherlands). 2024 Mar 12*** epublish ***
Adri M Durant, Yeonsoo S Lee, Lanyu Mi, Kassem Faraj, Timothy D Lyon, Parminder Singh, Mark D Tyson Ii
Department of Urology, Mayo Clinic, Phoenix, AZ, USA., Mayo Clinic Alix School of Medicine - Florida campus, Mayo Clinic College of Medicine and Science, Jacksonville, FL, USA., Division of Clinical Trials and Biostatistics, Mayo Clinic, Scottsdale, AZ, USA., Department of Urology, University of Michigan, Ann Arbor, MI, USA., Department of Urology, Mayo Clinic, Jacksonville, FL, USA., Division of Hematology and Medical Oncology, Department of Internal Medicine, Mayo Clinic, Phoenix, AZ, USA.