Immunologic Interreactions in Neoplastic Diseases.

The article focuses on immunologic aspects involved in neoplastic diseases. The immune system of the body is directed against foreign antigens and newly antigenic cells. It has been hypothesized that one function of the immune system is to maintain a surveillance of the body for weakly antigenic neoplastic cells, and to destroy continually appearing potentially malignant cells by this immunosurveillance mechanism. The end result of any weakening of the immunosurveillance system is neoplastic cellular proliferation. Tumor antigens have been detected by various technics, including complement fixation, fluorescent antibody, precipitin and agglutinin reactions. Such technics reflect the humoral antibodies developed against tumor antigens which are circulating in most instances. Thus, serum precipitating antibodies which react with an antigen from colonic adenocarcinoma have been discovered. This antigenic substance is the same as that found in embryonic colon mucosa and has been named carcinoembryonic antigen. It is present in the circulation of affected patients until they are cured. The antigen also has been discovered in the sera of pregnant women and presumptively arises from their fetuses. It has been suggested that screening be done for this antigen in the precancerous stages of ulcerative colitis and gastrointestinal polyposis, as an early cancer detection device.