Immunological approaches to cancer treatment.

Immunological approaches to cancer treatment are reviewed to consider the role of specifically sensitized effector cells as well as non-specific mechanisms. The induction of immunity by specific mechanisms is exemplified by the response to carcinogen induced animal tumours but this is contrasted with the lack of this type of response with naturally occurring animal tumours. These experimental findings are reviewed in relation to the clinical approaches to active immunotherapy. Regional immunotherapy, where bacterial adjuvants are administered so as to localize in tumour deposits is generally more effective than systemic immunotherapy. This is discussed in relation to the animal studies and these approaches are reviewed, particularly in connection with the treatment of human lung cancer.