Ductular carcinoma of the breast: serum antibodies to tumor-associated antigens.

Serum antibodies to tumor-associated antigens of breast carcinoma have been studied by indirect immunofluorescence in 109 patients with breast carcinoma and 125 controls, including age/sex matched normal individuals, patients with nonmalignant disease, and patients with malignant disease other than breast cancer. We report here that sera of a large proportion of patients with ductular carcinoma of the breast have antibodies to cell surface and/or intracellular antigens of autologous tumor cells and include evidence that the antigens are absent from a considerable range of normal and other types of malignant tissues. In addition to testing of control sera, specificity of the reacting antibodies was investigated further by testing of sera with normal breast tissue and the absorption of sera from breast cancer patients with various normal tissues and cancer cells. The significance of the findings in breast cancer is discussed.