[Diagnostic value of urinary N-telopeptide of type I collagen in prostate cancer: comparison with bone scintigraphy].
The usefulness of a new biochemical marker of bone resorption, N-telopeptide of type I collagen (NTx), in the diagnosis of bone metastasis was assessed in 69 prostate cancer patients. Based on the bone scintigraphy findings, the patients were divided into a bone metastasis (+) group (n = 36) and a bone metastasis (-) group (n = 33). The urinary NTx level was significantly higher in the bone metastasis (+) group than in the bone metastasis (-) group (95.5 +/- 18.5 nM BCE/mM Cr vs. 63.3 +/- 7.9 nM BCE/mM Cr). There was a tendency for greater variability in urinary NTx levels during a 2 month-period in the bone metastasis (+) group than in the bone metastasis (-) group. The urinary NTx level of the 6 patients who were clinically staged as (4+) according to the extent of disease (EOD) grading system was 211.4 +/- 96.9 nM BCE/mM Cr, and was significantly higher (p < 0.05) than in the (-) group. However, there was not a significant difference in urinary NTx levels between the (1+) to (3+) groups and the (-) group. In conclusion, measuring urinary NTx levels in useful in diagnosing bone metastasis in view of the fact that it is a simple and noninvasive procedure. While it is not as sensitive as bone scintigraphy, it may be used to supplement bone scintigraphy.