Abstract:

Objective To explore the diagnostic value of emission computed tomography （ECT） combined with serum fibroblast growth factor 23 （FGF23） and angiopoietin-like protein 2 （Angptl-2） for bone metastasis in lung cancer patients. Methods A total of 127 patients suspected of having bone metastasis from lung cancer at First Affiliated Hospital of Xi'an Jiaotong University from June 2023 to June 2025 were included as the study subjects. ELISA method was used to measure the levels of serum FGF23 and Angptl-2. The Bayesian log-binomial regression model was used to evaluate the effects of the levels of FGF23 and Angptl-2 on bone metastasis in lung cancer patients. Receiver operator characteristic （ROC） curve was used to analyze the diagnostic efficacy of serum FGF23 and Angptl-2 levels for bone metastasis in lung cancer patients； Four grid table method was used to analyze the diagnostic value of ECT combined with serum FGF23 and Angptl-2 levels for bone metastasis in lung cancer patients. Results Taking the pathological results of bone biopsy as the gold standard， among 127 patients with suspected bone metastasis of lung cancer， 53 cases had bone metastasis and 74 cases didn't have bone metastasis. The levels of serum FGF23 and Angptl-2 in patients with bone metastasis were （123.46±22.18） pg/ml and （32.46±5.13） ng/ml， respectively， while those in patients without bone metastasis were （98.37±16.21） pg/ml and （26.52±4.15） ng/ml， respectively. Compared with patients without bone metastasis， the levels of serum FGF23 and Angptl-2 in patients with bone metastasis were both relatively higher， with statistically significant differences （t=7.37， P<0.001； t=7.20， P<0.001）. The risk of bone metastasis in patients with high levels of serum FGF23 and Angptl-2 was 2.96 times and 2.66 times that of patients with low levels， respectively. The ROC curve analysis showed that， the area under the curve （AUC） of serum FGF23 and Angptl-2 levels in diagnosing bone metastasis in lung cancer patients was 0.77 and 0.81， respectively， the sensitivities were 69.81% and 66.04%， respectively， the specificities were 82.43% and 87.84%， respectively， and the accuracies were 77.17% and 78.74%， respectively. The sensitivity of ECT in diagnosing bone metastasis in lung cancer patients was 79.25%， the specificity was 83.78%， and the accuracy was 81.89%. The sensitivity of ECT combined with serum FGF23 and Angptl-2 in diagnosing bone metastasis in lung cancer patients was 98.11%， the specificity was 81.08%， and the accuracy was 88.19%. The sensitivity of combined diagnosis was higher than that of serum FGF23， Angptl-2 and ECT alone （χ²=15.76， P<0.001； χ²=18.53， P<0.001； χ²=9.40， P=0.002）， and the accuracy of combined diagnosis was higher than that of serum FGF23 and Angptl-2 alone （χ²=5.39， P=0.020； χ²=4.11， P=0.043）. Conclusions Patients with lung cancer bone metastasis have higher levels of serum FGF23 and Angptl-2. ECT combined with serum FGF23 and Angptl-2 levels has a higher diagnostic value for bone metastasis in lung cancer patients compared to the individual detection of each indicator.

Key words: Lung neoplasms, Neoplasm metastasis, Fibroblast growth factors, Angiopoietin-like proteins, Radionuclide bone imaging