Carcinoembryonic antigen in serum of unselected breast-cancer patients and of non-hospitalized controls.

A series of consecutive unselected patients with primary breast carcinoma and their age-matched controls were studied for serum CEA in relation to clinical findings. Raised CEA was found in a similar frequency in patients with primary breast cancer (pre- and postoperative) and in the control women: 16%, 11% and 11%, respectively, exceeded the selected upper limit of the reference range (13 ng/ml) with a double-antibody radioimmunoassay. In the breast-cancer patients, however, 48% of the raised CEA levels exceeded 16 ng/ml, compared with only 20% in the controls. Significant correlations (r approximately 0.3) were found between CEA levels and tumour size, TNM classification and a combined clinical and histopathological classification. A high frequency of raised CEA values in the advanced breast-cancer patients was the essential contribution to these positive correlations. A correlation coefficient of 0.6 was found between pre- and postoperative CEA values. The frequency of smoking and/or chronic disease was unexpectedly high in patients as well as in controls with high CEA.