Serum N-telopeptide of type I collagen and bone alkaline phosphatase and their relationship in patients with non-small cell lung carcinoma and bone metastases

Patients and Methods: Thirty-five patients (24 mean, 11 women, median age 63 years, range 51 72 years) with NSCLC were examined: 16 patients with confirmed BMs (Group A), and 19 agematched (63.5±4.9 vs. 63.7±4.4 years; p = 0.88) patients without BMs (Group B). Serum levels of bone resorption marker cross-linked amino-terminal telopeptide of type I collagen (NTx), and bone formation marker bone alkaline phosphatase (BAP) were measured in both groups by enzyme-linked immunosorbent assay. Results: NTx (33.5±7.2 vs. 25.6±3.1 nM BCE), and BAP (51.7±6.0 vs. 40.7±7.3 U/L) serum levels were significantly (p < 0.001) different between groups (A vs. B). No correlation was found between age and both NTx (R = 0.34, p = 0.08) and BAP (R = 0.10, p = 0.61) among patients with BMS. Using a cut-off value of 30 (TNx) and 50 (BAP), the sensitivity and specificity were 53.6% and 90.3% TNx), 38.7% and 87.1% (BAP) (OR = 0.46, 95% CI 0.16 1.32, p = 0.15). Conclusions: In patients with NSCLC both NTx and BAP are specific bone remodelling markers, but their usefulness is limited in early diagnosis of BMs.