Immunotherapy of cancer. Present Status and Future Potential

The demonstration of tumor-specific antigens in human cancers revived interest in immunotherapy as a mode of treatment. Evidence accumulated suggests that the cancer patient's immune response to these tumor-specific antigens is important in controlling the development and progression of his disease. Those patients who can demonstrate an active immune system have a better prognosis than those with a general depression in their immune reactivity. Three possible approaches to immune therapy of cancer are reviewed and discussed: active immunotherapy, passive immunotherapy, and nonspecific immunotherapy. The rational application of immunotherapy to human cancer will depend upon a better knowledge of the nature of the tumor-specific antigens in human neoplasms and methods for increasing the immune response against these antigens. It is necessary to define by laboratory study those immune responses that best correlate with clinical course and then develop immunotherapy programs to stimulate those responses in the cancer patient. The future of immunotherapy in human cancer is bright, and results will improve as this knowledge grows.