Serum tumor markers for detection of bone metastasis in breast cancer patients.

For the diagnosis of bone metastasis in breast cancer patients during systemic treatment serum tumor markers, including carbohydrate antigens 15-3 (CA 15-3) and 19-9 (CA 19-9), cancer antigen 125 (CA 125), alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), beta-2 microglobulin (BMG), ferritin, and tissue polypeptide antigen (determined by the M3 monoclonal antibody, TPS) were measured in 22 patients with known bone metastases and in 30 patients without documented metastases. The most useful single marker was CA 15-3. By stepwise discriminant analysis, it was found that 90% of the patients could be diagnosed truly by using the markers CA 15-3, BMG and ferritin. It is concluded that monitoring with combinations of tumor markers at regular intervals increases the diagnostic efficiency.