BCG in the treatment of superficial cancer of the bladder: a review.

Superficial Bladder Cancer can be treated in several ways. During the last decades, intravesical instillation of Bacillus Calmette Guerin (BCG) has emerged as an effective therapy. The history of how BCG became an antitumoral treatment is long and intriguing, and the theoretical background is fragile. In numerous studies, involving over 3,000 patients, intravesical instillation of BCG has been shown to be an effective treatment for superficial cancer of the urinary bladder in humans. Temporarily, BCG can eradicate residual disease after surgery, it can prevent local recurrence, and it can halt deterioration of malignancy in recurrences. However, its effect on survival is uncertain. For patients, treatment with BCG is prolonged, expensive, associated with side-effects, and may even be harmful. The mode of action is obscure. The theoretical framework on which this therapy is based is purely speculative, if existing at all. Although BCG has been classified as a biological response modifier, and the treatment is termed immunotherapy, proof is still lacking that the mechanism is immunological.