title: The clinical importance of bone metabolic markers in detecting bone metastasis of lung cancer.
abstract: OBJECTIVE
  The aim of this study was to evaluate the role of bone metabolic markers in clinical evaluation of bone metastasis of lung cancer.
  
  
  METHODS
  Sixty-five male patients with lung cancer were included in this trial, 77% of whom were diagnosed as having non-small cell lung cancer and 20% were small cell lung cancer. The presence of bone metastasis was investigated by whole-body bone scintigraphy via Tc-99m mostly (80%) and, in some cases, PET/CT (positron emission tomography and computerized tomography) which was performed for staging. Bone-specific alkaline phosphatase (BALP) and osteocalcin were measured in serum of the patients as markers of bone formation. N-terminal telopeptide (NTX) and β-form of C terminal telopeptide (β-CTX) were studied as bone destruction markers.
  
  
  RESULTS
  The cases were divided into two groups according to the presence of bone metastasis. Twenty-three patients (35%) had bone metastasis. Serum levels of total ALP, BALP and NTX were significantly higher in the group with bone metastasis (p < 0.05). Osteocalcin and β-CTX levels were not significantly different between two groups. According to ROC-curve analysis, at the threshold value of 22.38 μg/L, the sensitivity of BALP was 60.87% and the specificity was 69.05%. Similarly, at the threshold value of 25.69 nmol BCE, the sensitivity of NTX was 90.24% and the specificity was 43.4%.
  
  
  CONCLUSIONS
  Bone metabolic markers are considered noninvasive, useful and cost-effective. However, more prospective studies are needed in order to use them for evaluation of bone metastasis in lung cancer.
authors.affiliation: Department of Pulmonary Medicine, School of Medicine, Adnan Menderes University, Aydin, Turkey.
authors.forename: Suna Bilgin
authors.initials: SB
authors.lastname: Bayrak
authors.forename: Emel
authors.initials: E
authors.lastname: Ceylan
authors.forename: Mukadder
authors.initials: M
authors.lastname: Serter
authors.forename: Fisun
authors.initials: F
authors.lastname: Karadağ
authors.forename: Ece
authors.initials: E
authors.lastname: Demir
authors.forename: Orhan
authors.initials: O
authors.lastname: Çildağ
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D001859:Bone Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000556:secondary; D024042:Collagen Type I / Q000097:blood*; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D015675:Osteocalcin / Q000097:blood; D010455:Peptides / Q000097:blood*; D049268:Positron-Emission Tomography; D012372:ROC Curve; D014057:Tomography, X-Ray Computed
chemical_list: D014408:Biomarkers, Tumor; D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin; D000469:Alkaline Phosphatase