The clinical importance of bone metabolic markers in detecting bone metastasis of lung cancer.

AIM: The aim of this study was to evaluate the role of bone metabolic markers in clinical evaluation of bone metastasis of lung cancer. MATERIALS AND 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 ß-form of C terminal telopeptide (ß-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 ß-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%. CONCLUSION: 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.