Immunologic approaches to the diagnosis of cancer.

A variety of immunologic approaches can be applied to the diagnosis of human cancer, and these have the potential advantages of specificity and sensitivity. Many tumor distinctive markers have been detected in the circulation of cancer patients. Cancer patients frequently have detectably depressed immune competence, but also have cell-mediated and humoral immune reactivity against tumor-associated antigens. Radiolabeling of specific antibodies may allow localization in vivo of tumors. With each of these potential immunodiagnostic approaches, it is necessary to systematically evaluate the assays and determine their value for specific clinical applications.