Axillary lymphoscintigraphy by radioimmunodetection of carcinoembryonic antigen in breast cancer.

In seven women with carcinoma of the breast I-131-labeled antibodies to carcinoembryonic antigen (CEA) were administered subcutaneously in the finger webs. Subsequent scintigraphic immages demonstrated localization of radioactivity in the ipsilateral axillary metastases of all patients and in the contralateral axillae of three. Fifteen patients with either gastrointestinal or genitourinary cancers were studied as controls; in 12 both the hands and feet were injected with antibodies to CEA and in the other three either the hands or feet. Radioactivity was observed in the inquinal nodes of four control patients with tumors below the diaphragm and in the axillary nodes of one patient with a tumor above the diaphragm. The concentration of antibody in lymph node metastases from breast carcinoma was 100% specific. In those lymph nodes that presumably contained no metastatic tumor but demonstrated localization of labeled antibody, retention of CEA in the nodes from tumor drainage is postulated as the receptor site for the antibody.