USEFULNESS OF PYRIDINIUM CROSS-LINKS AND CA-15-3 AS MARKERS IN METASTATIC BONE BREAST-CARCINOMA

Numerous tumor markers such as CEA, MCA, CA 15-3 have been assayed in breast cancer patients to detect relapse at a preclinical stage and mo st of all to monitor the treatment of the advance disease. Since they are not site-specific, pyridinium crosslink dosage has recently been r eported as a specific bone resorption marker in several non neoplastic disease. The aim of this study was to evaluate the urinary pyridinium crosslink levels in breast cancer with or without osseous involvement , and to correlate it with serial doses of CA 15-3. 285 breast cancer patients (226 free of disease and 59 with bone metastases) were measur ed for both pyridinoline and CA 15-3. In the metastatic patients the m ean values of the two markers were significantly higher than in non ev ident disease patients (P = <0.01 and p = <0.001 respectively). Abnorm al values over the normal were found in 22% for pyridinoline and 11% f or CA 15-3 in patients free of disease while the normal values observe d in patients with bone metastases were 22% for pyridinoline and 39% f or CA 15-3. Tandem dosage of CA 15-3, was highly sensitive but site-as pecific, and pyridinoline, which is bone specific, may be useful chief ly in the monitoring of breast cancer treatment, since many physiologi cal conditions such as age, menopausal status and variation over 24 ho urs, and cost effectiveness will influence the use of pyridinoline dur ing follow-up.