Diagnostic and Prognostic Value of Serum Angiopoietin-Like Protein 2 in Patients with Non-Small Cell Lung Cancer.

BACKGROUND: Elevated serum angiopoietin-like protein 2 (ANGPTL2) level has been observed in several different types of cancer, but it remains unclear in non-small cell lung cancer (NSCLC). The present study aimed to explore serum ANGPTL2 in sera from NSCLC patients and analyze the association of serum ANGPTL2 with patient diagnosis and prognosis.

METHODS: Enzyme Linked Immunosorbent Assay (ELISA) was used to measure serum ANGPTL2 concentration. The associations of serum ANGPTL2 level with clinicopathological characteristics of NSCLC patients were further analyzed. ROC/AUC analysis and Kaplan-Meier analysis were performed to evaluate its diagnostic and prognostic value in NSCLC patients.

RESULTS: Serum ANGPTL2 was significantly higher in NSCLC patients (8.38 ± 1.73 vs. 4.87 ± 0.96 ng/mL; p < 0.01). Higher serum ANGPTL2 could be observed in NSCLC patients with late TNM stage, lymph node metastases, distant metastases, and poor differentiation compared to those with early TNM stage, without metastases, and well/moderate differentiation. The ROC/AUC analysis yielded an AUC of 0.86 (0.83 - 0.90) (sensitivity of 0.83, specificity of 0.82) to distinguish NSCLC patients from normal controls, while serum ANGPTL2 was also an efficient indicator to distinguish NSCLC patients with late clinical stage from early stages with an AUC of 0.92 (95% CI 0.89 - 0.95) with sensitivity of 0.91, specificity of 0.86. Prognostic analysis showed that NSCLC patients with high serum ANGPTL2 levels had lower survival rates than those with low levels (p < 0.01 for log-rank test).

CONCLUSIONS: Serum ANGPTL2 levels were significantly increased in NSCLC patients, which could serve as a novel potential diagnostic and prognostic biomarker for NSCLC.