Serum concentration of pyridinoline cross-linked carboxyterminal telopeptide of type I collagen in patients with metastatic breast cancer.

The serum concentration of pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP) was examined in 83 patients with metastatic breast cancer. ICTP levels were significantly higher in patients with bone metastases than in those without bone metastasis. In patients with bone metastasis, significantly higher ICTP levels were observed in those with multiple lesions than in those with a solitary lesion and these levels reflected therapeutic response. Sequential monitoring of ICTP revealed that this elevation was correlated with disease progression. Combined with imaging studies, monitoring of ICTP appears to offer additional information for detection of bone metastasis and evaluation of therapeutic response to bone metastasis.