The management of BCG failure in non-muscle-invasive bladder cancer: an update

Abstract

Up to 40% of patients with non-muscle-invasive bladder cancer(NMIBC) will fail intravesical bacillus Calmette-Guérin (BCG)therapy. There is unfortunately no current gold standard for salvageintravesical therapy after appropriate BCG treatment. Indeed,outcomes are at best suboptimal. The vast majority of low-gradeNMIBC are prone to recur but very rarely progress. Failure afterintravesical BCG in these patients is usually superficial and lowgrade.At the other end of the spectrum, failure to respond to BCGin high-risk T1 bladder cancer and/or carcinoma in situ (CIS orTIS) is more problematic, since those tumours often have the potentialto progress to muscle invasion. In these cases, radical cystectomyremains the mainstay after BCG failure. With appropriateselection, certain patients who “fail” BCG (but with favourablerisk factors) can be managed with intravesical regimens, includingrepeated BCG, BCG plus cytokines, intravesical chemotherapy,thermochemotherapy or new immunotherapeutic modalities. Inthis review, reasons explaining BCG failure, how to define BCGfailure, optimal risk stratification and prediction of response andmanagement of BCG failures are discussed.