Serum Cross-Linked N-Telopeptide Of Type I Collagen As A Biomarker Of Bone Metastases For Patients With Lung Cancer: A Meta-Analysis

Objective: Bone metastasis is one of the most common events for lung cancer patients. The aim of this study was to investigate serum cross-linked N-telopeptide of type I collagen (NTx) as a biomarker for bone metastases in patients with lung cancer by pooling published studies. Methods: Open published studies about serum crosslinked N-telopeptide of type I collagen (NTx), as a biomarker of bone metastases for patients with lung cancer, were electronically searched in databases of Pubmed, Embase, and CNKI by two reviewers (Yanjun Su and Hui Chen), independently. Relevant studies were included in this met-analysis and data of each included study were extracted. Mean NTx levels of bone metastases lung cancer (case group) and non-bone metastases lung cancer (control group) of each individual publication was compared. Using serum NTx as a biomarker, diagnostic sensitivity (sen), specificity (sep), positive likelihood ratio (+lr), negative likelihood ratio (-lr), diagnosis odds ratio (dor), and area under the received operative curve (AUC) for bone metastases were pooled by a meta-analysis method, through random or fixed effects models. Results: Eleven studies were included for quantitative analysis and 9 studies for meta-analysis. Serum levels of NTx for bone metastases lung cancer and non-bone metastases lung cancer were 28.82 +/- 7.74 nmol/L and 17.11 +/- 5.26 nmol/L, respectively, indicating that serum level of NTx in the metastases disease group was significant higher than non-metastases disease group (t=3.34, P=0.003). Combined data showed pooled sensitivity and specificity were 0.79 (95% CI: 0.73-0.83), respectively. Pooled +lr, -lr, and dor were 2.83 (95% CI: 1.98-4.06), 0.28 (95% CI: 0.18-0.45), and 11.60 (95% CI: 6.26-21.49), respectively, through a random effects model. Systematic area under ROC curve (AUC) was calculated using data from each individual study. Pooled AUC was 0.84. Conclusion: Serum NTx levels were significant elevated in bone metastases lung cancer. This could be a potential biomarker for bone metastases diagnosis with relative high sensitivity and specificity.