NEW YORK (Reuters Health) – Intravesical bacille Calmette-Guérin (BCG) therapy for bladder cancer is associated with eradication of uropathogens in patients not taking antibiotics, according to a new study.

Intravesical BCG is standard therapy for high-grade noninvasive bladder cancer and may persist in the bladder wall for up to 2 years.

Dr. Harry W. Herr from Memorial Sloan-Kettering Cancer Center, New York, hypothesized that the enhanced immune response generated by BCG against tumor cells augments innate immune defenses that could eradicate infected bladder epithelial cells and thereby clear the urine of chronic bacteriuria without the use of antibiotics.

He tested this hypothesis in a prospective cohort study of 89 bladder cancer patients with bacteriuria who received BCG therapy and 89 bacteriuric cystoscopy patients who were not treated with BCG. Both groups were followed without antibiotic treatment for at least 1 year.

Fifty-eight (66%) of the BCG-treated patients became continuously infection-free, compared to only 16 (18%) of the cystoscopy patients (p=0.001).

Most patients were infected with Escherichia coli or Enterococcus, and there was no difference in distribution of organisms between BCG-treated or cystoscopy patients.

“Intravesical BCG therapy appears to eradicate urinary tract uropathogens and malignant cells in antibiotic-naïve bladder cancer patients, possibly due to active and augmented innate host immunity,” Dr. Herr concludes in his report, published online August 20 in European Urology. “The study design, however, does not allow inference of a causal effect of BCG on bacteriuria.”

Intravesical BCG is FDA-approved for the treatment and prophylaxis of carcinoma in situ (CIS) of the urinary bladder and for the prophylaxis of primary or recurrent state Ta and/or T1 papillary tumors following transurethral resection (TUR). It is not approved for treatment of bacteriuria.

Dr. Herr did not respond to a request for comments.

SOURCE: Intravesical Bacille Calmette-Guérin Eradicates Bacteriuria in Antibiotic-naïve Bladder Cancer Patients

Eur Uro 2012.