Evidence for Cancer-specific Antigens in Man

Abstract
The evidence for the existence of human cancer-specific antigens, that is, antigens which are present in cancer and not present in the normal tissues of the same persons, is reviewed. Clinical observations, experiments based on the natural course of tumor growth, tumor transplantation, tumor vaccination, cellular mechanisms of immunologic response, serologic method of antigenic analysis, and skin tests are reviewed and evaluated. The difficulty of detecting and distinguishing the individual components of a complex mixture of antigens is emphasized as the major technical problem and the major source of error in the search for cancer-specific antigens. Most of the studies which purport to show cancer-specific antigens have probably shown only differences in the tissue antigens of different people. However, some of the more recent and stringently controlled studies have so greatly reduced this source of error that probably the more recently observed antigenic differences are actually cancer-specific. Further investigations with appropriate comparison of normal and neoplastic tissues from the same persons are necessary.