BCG in cancer and leukemia treatment and prophylaxis-A review.

Five international oncology meetings crystallized the concept that the immune system plays a dominant role in the prevention and inhibition of neoplasia; that the cancer antigens are relatively weak, therefore eliminating weak or uneffective cellular immunity which is paramount in tumor rejection; that humoral antibodies against neoplastic antigens may block the cytotoxic action of T cells against the tumor cells. A number of agents have been found capable of stimulating the immune system (T-cell activation) but from a clinical standpoint BCG had had the widest application in a variety of tumors and leukemia. Thus the emphasis in this review will be on BCG.