Intravesical bacille Calmette-Guérin eradicates bacteriuria in antibiotic-naïve bladder cancer patients

Intravesical bacille Calmette-Guérin (BCG) therapy is safe and effective in bladder cancer patients who have asymptomatic bacteriuria. BCG induces robust immune responses in the bladder that are responsible for its antitumor effect. We hypothesize that BCG-induced inflammation may eradicate bacterial infection.

To investigate whether intravesical BCG therapy alone can eradicate bacterial infection in antibiotic-naïve bladder tumor patients who have asymptomatic bacteriuria.

A single-institution prospective cohort study of bacteriuric adults with non-muscle-invasive bladder tumors who underwent outpatient BCG therapy or surveillance cystoscopy.

Ninety high-risk patients received induction intravesical BCG without maintenance BCG, and 95 low-risk patients who had not received BCG underwent outpatient surveillance cystoscopy. Each patient had significant bacteriuria on urine culture, and none received routine antibiotics before, during, or after procedures.

Urine cultures were repeated after 3, 6, and 12 mo. All patients had follow-up cystoscopy every 3 mo and were followed for a minimum of 1 yr. The end point was number of BCG-treated and cystoscopy patients who became bacteria free at 3, 6, and 12 mo.

Two BCG-treated patients (2.2%) and six patients after cystoscopy (6%) developed febrile urinary tract infection (p=0.21). All resolved with antibiotics. No patient was admitted for sepsis. Of 88 infected patients who received BCG without routine antibiotics, 58 (66%) were continuously bacteria free at 1 yr compared with 16 of 89 cystoscopy patients (18%; p=0.001). The prospective observational study design prohibits causal inference of antibacterial effects attributed to BCG over cystoscopy.

Intravesical BCG therapy is associated with clearance of uropathogens in bladder cancer patients, possibly due to augmented innate host immunity.