DIAGNOSTIC VALIDITY OF BONE METABOLIC MARKERS FOR BONE METASTASIS

We measured bone resorption markers in tumor patients with and without bone metastases and evaluated the diagnostic validity of these bioche mical parameters in the diagnosis of neoplastic bone involvement. On t he basis of radiography and bone scintigraphy findings, subjects were divided into 3 groups, 83 patients without bone metastases (META(-)), 22 patients with 1 or 2 bone metastases (META(+)) and 22 patients with more than 3 bone metastases (META(++)). Among the biochemical markers , urinary pyridinoline (PYR), circulating C-terminal telopeptide of ty pe I collagen (ICTP) and urinary N-terminal telopeptide of type I coll agen (NTx) were especially sensitive and specific and increased signif icantly not only in META(++) but also even in META(+). The efficacy of several bone metabolic markers in differentiating between patients wi th and without bone metastases was evaluated by receiver-operating cha racteristic (ROC) analysis, and PYR, ICTP and NTx were proved to have high diagnostic validity (area under the ROC curve; 0.75 for PYR, 0.77 for ICTP and 0.77 for NTx). Furthermore, their odds ratios showed sig nificantly high values for both META(+) and META(++)(to META(++); 7.91 for PYR, 5.33 for ICTP and 5.70 for NTx). On the other hand, urinary deoxypyridinoline (DPYR) and serum total alkaline phosphatase (ALP) sh owed relatively low sensitivities, the odds ratio of ALP in particular being insignificant. In conclusion, several bone metabolic markers we re proved to be useful in the diagnosis of bone metastases in patients with malignancies, particularly PYR, ICTP and NTx had rather high dia gnostic validities among all markers examined in this study.