[Radioimmunoassay of carcinoembryonic antigen in the evaluation of the effectiveness of breast cancer treatment].

Changes in blood--CEA level in the course of tumor process were studied in 123 cases of breast cancer. In primary tumor patients, CEA concentration was found to be in correlation with tumor expansion. It depended upon the degree of involvement of regional lymphatics rather than on the size of primary tumor, since the involvement of lymph nodes was matched by an increase in CEA level. A persistent decline in CEA concentration during and after treatment served as an indication that the latter was adequate. A steady rise in CEA level despite treatment was prognostically unfavorable. It preceded clinical manifestations of metastases.