Urinary carboxyterminal telopeptide of collagen I as a potential marker ofbone metastases chemotherapy monitoring in breast cancer

Breast cancers frequently have osteoclastic bone metastases that are diffic ult to monitor and treat. Bone scintigraphy with Tc-99m-labeled biphosphona tes is still the reference method for detecting and localizing bone involve ment. Classical biochemical markers such as urinary calcium have poor sensi tivity for detecting and monitoring metastases of breast cancers. New bioch emical markers for the study of bone remodeling have recently been develope d, including a degradation product of the C-terminal end of the telopeptide of type I collagen (CTX). We used an immunoenzymatic assay technique for u rinary CTX in 84 pre- and post-menopausal women and demonstrated a correlat ion between scintigraphic scores and urinary CTX concentrations. CTX values are significantly different between the control group and patients with bo ne metastasis, except those with score 0. There is a regular increase in ur inary CTX concentration from score 0 (no abnormal uptake) to score 4 (diffu se carcinomatosis). There is no significant variation between control popul ation and score 0 to 3 for urinary calcium. Only women with scintigraphic s core 4 have significantly increased urinary calcium concentrations. Measuri ng CTX in pre- and postmenopausal patients during breast cancer chemotherap y might be of great interest for monitoring the development of metastases a nd the therapeutic efficacy of chemotherapy. (C) 1999 Elsevier Science B.V. All rights reserved.