Diagnostic value of bone-turnover metabolites in the diagnosis of bone metastases in patients with lung carcinoma

BACKGROUND. Several biochemical markers of bone formation and bone resorpti on have been developed recently. The authors evaluated the usefulness of ne w biomarkers, such as urinary deoxypyridinoline (D-PYD), serum pyridinoline crosslinked C-telopeptides of Type I collagen (1CTP), and urinary pyridino line crosslinked N-telopeptides of Type I collagen (NTx), in the assessment of bone metastases in patients with lung carcinoma. METHODS, The serum concentrations of 1CTP and the urinary concentrations of D-PYD and NTx were measured in 100 lung carcinoma patients, of whom 20 pat ients had bone metastases and 80 patients did not. Receiver operating chara cteristic (ROC) curves were drawn for these markers to compare their useful ness in detecting bone metastases originating in lung carcinoma. RESULTS. Urinary concentrations of NTx in patients with bone metastases wer e significantly greater than in patients without bone metastases (147.1 +/- 129.3 pmol bone collagen equivalents [BCE]/mu mol Cr vs. 47.2 +/- 29.9 pmo l BCE/mu mol Cr; P < 0.0001). Urinary concentrations of D-PYD in patients w ith bone metastases also were significantly greater than in patients withou t bone metastases (10.0 +/- 3.6 BCE/<mu>mol Cr vs. 6.6 +/- 2.2 pmol BCE/mu mol Cr; P = 0.0001). No significant difference was observed in serum concen trations of 1CTP between patients with and without bone metastase. A modera te but significant correlation was seen between NTx and D-PYD (correlation coefficient [R] = 0.435; P < 0.0001) and between D-PYD and 1CTP (R = 0.525; Pt 0.0001). NTx had a better ROC curve than D-PM and 1CTP (the areas under the ROC curve were 0.84, 0.79, and 0.62, respectively). Using the threshol d of 62.5 pmol BCE/<mu>mol Cr for NTx, sensitivity, specificity, and accura cy were 0.800, 0.737, and 0.750, respectively. CONCLUSIONS. In the current study, the measurement of NTx appeared to be mo st useful as a marker of bone metastases in patients with lung carcinoma. C ancer 2001;91:1487-93. (C) 2001 American Cancer Society.