Comparison of serum beta 2-microglobulin and carcinoembryonic antigen (CEA) in the follow-up of breast cancer patients.

Using commercially available radioimmune test kits, serial determinations of serum beta 2-microglobulin and CEA were performed in 337 patients, who had been treated for breast cancer by modified radical mastectomy and radiotherapy. The pre-therapeutic data indicated a higher incidence of pathological beta 2-microglobulin and CEA levels in patients with distant metastases than in patients with localized disease. However, this finding did not allow the conclusion of a direct complementarity of beta 2-microglobulin and CEA as tumour markers, since the group of patients with distant metastasis contained a high percentage of elderly patients who generally can be expected to have elevated beta 2-microglobulin serum concentrations. Therefore, the correlation of the clinical course of malignant disease and the incidence of relapses with the changes of serum beta 2-microglobulin and CEA concentrations was examined during the post-treatment surveillance: 7/9 cases (78%) with local recurrence and 46/73 cases (63%) with distant spread of disease were not indicated in the beta 2-microglobulin follow-up by pathologic serum concentrations, whereas in the CEA follow-up only 1/9 and 2/73 false negative indications were registered. The poor correlation suggests that serum beta 2-microglobulin is not directly tumour associated in breast cancer and does not fulfill the criteria of a tumour marker.