Objective   This study was aimed to investigate the value of osteoclast differentiation factor (ODF) and osteoclastogenesis inhibitory factor (OCIF) detection for clinical diagnosis and assessment of patient condition in bone metastasis of lung cancer.

  Methods   Data from 186 lung cancer patients who were preliminary diagnosed between July 2009 and April 2012 were analyzed. Cases were divided into the bone metastasis group with 82 cases (group A) and the non-bone metastasis group with 104 cases (group B). Concentrations of serum ODF and OCIF in each group were detected by ELISA.

  Results   ODF and OCIF values of group A were (32.22±6.22) ng/L and (41.23±8.13) ng/L, respectively, which were significantly higher than the corresponding values in group B (8.35 ±5.42) ng/L and (10.15±4.42) ng/L. The differences between the two groups were statistically significant (P < 0.01). Areas under the receiver operating characteristic curves of ODF and OCIF, which are used to diagnose bone metastasis in lung cancer, were 0.91 and 0.87, respectively, manifesting good diagnostic value. The sensitivity and specificity of ODF in diagnosing lung cancer with bone metastasis were 90.38% and 86.59%, respectively, and those of OCIF were 86.54% and 84.15%, respectively. ODF increased, whereas OCIF decreased significantly, with increasing bone metastasis. ODF and OCIF concentrations in group A and the group with newly-found bone metastasis were significantly higher than those in group B, with statistically significant differences among these groups (P< 0.01). Compared with group A, less difference was found in the ODF and OCIF of newly-found bone metastases, without statistical significance between these groups (P>0.05).

  Conclusion   Conclusion: The serum ODF and OCIF concentrations significantly increase when bone metastasis occurs in lung cancer patients. Hence, these variables are useful as indices for monitoring bone metastases and evaluating patient condition. An extensive application prospect is proposed.