BCG Immunotherapy for Superficial Bladder Cancer: An Overview of the Past, the Present and the Future

Abstract

Objectives: The role of intravesical immunotherapy with bacillus Calmette-Guérin (BCG) for the treatment of superficial bladder cancer is discussed and the achievements of the past 25 years are reviewed.

Method: Evidence based results for clinical trials as well as from basic research are used in trying to answer a number of questions relevant for the use of BCG.

Results: The exact working mechanism of BCG has not been revealed yet. Clinical and basic research have shown that the best route of BCG administration is the intravesical route. BCG is superior to intravesical chemotherapy for preventing recurrence. Recently it has been shown that BCG is able to prevent or delay invasion to muscle invasive bladder cancer. However to achieve this, maintenance therapy is necessary. Intermediate and high risk tumors can be treated with BCG, but for low risk tumors BCG should be avoided due to its possible side effects. No differences in efficacy have been found between the different strains. The presence or absence of side effects does not appear to be a prognostic factor for BCG efficacy and maintenance therapy is not associated with increased toxicity. In the future, the optimal scheme and dose should be defined and this is probably different for each individual.