Bacterial cells as anti-tumour agents in man.

Since conventional cancer treatments cannot guarantee the destruction of all the tumour cells present within the patient, a relatively new form of therapy has been introduced whereby bacteria are used to stimulate immune responses, which if properly generated have the potential to eliminate the few remaining tumour cells that escaped the conventional treatments. This review deals with the results of clinical trials of immunotherapy and demonstrates that although it could form the basis of an effective therapy, it still requires more experiments to increase its efficiency and to decrease its side effects, the most serious of which is to accelerate tumour growth in some instances. The review concentrates on the two main agents currently in use, Bacillus Calmette-Guérin and Corynebacterium parvum.