Immunology, tumor markers, and breast cancer.

Although our knowledge of immunologic processes in breast cancer is still inadequate, many preliminary studies described here may yield valuable information after long-term patient follow-up. At present, there is no specific tumor marker diagnostic of breast cancer, but markers such as CEA, ferritin, immune complexes, and specially estrogen receptors have strong potential as prognostic indicators. As a group, breast cancer patients, as do those with other malignancies, demonstrate reduced immunologic capacity, therefore assays of nonspecific immune function may not be relevant. Assays of "specific" reactivity to breast tumor antigens, however, warrant further investigation as clinical tools. Application of immunotherapy to breast cancer is relatively recent and few trials have more than preliminary data. Determination of estrogen receptors should be included in future clinical immunotherapy protocols so that true evaluation of immunologic responses may benefit, hopefully, from our awareness of the endocrine milieu.