The combination assay with circulating vascular endothelial growth factor (VEGF)-C, matrix metalloproteinase-9, and VEGF for diagnosing lymph node metastasis in patients with non-small cell lung cancer

BACKGROUND: The aim of the present study was to evaluate the diagnostic utility of levels of circulating vascular endothelial growth factor (VEGF)-C, matrix metalloproteinase-9 (MMP-9), and VEGF and to verify that the combination assay of these circulating factors is a clinically useful indicator to predict the presence of lymph node metastasis in non-small cell lung cancer (NSCLC).

METHODS: A series of 78 patients who underwent surgery for NSCLC was used in this study. Serum VEGF-C and VEGF and plasma MMP-9 levels were analyzed with enzyme-linked immunosorbent assay (ELISA) kits. Logistic regression models were used to analyze the influence of VEGF-C, MMP, and VEGF levels on the probability of presence or absence of lymph node metastasis.

RESULTS: Patients with lymph node metastasis had higher serum VEGF- C, VEGF, and plasma MMP-9 concentrations than did those without metastasis (VEGF-C, P = .0004; VEGF, P = .001). Serum VEGF- C reached a sensitivity of 85% and specificity of 68% when a cutoff value of 1762.0 pg/mL was applied, while VEGF reached 80% sensitivity and 59% specificity at 316.8 pg/mL. MMP-9 reached a sensitivity of 63% and specificity of 75% when a cutoff value of 51.4 ng/mL was applied. In the ROC curve analysis, VEGF-C (0.761) had the biggest areas under the ROC curve, followed by MMP-9 (0.723) and VEGF (0.694). Combination assay of three markers had higher sensitivity and specificity for prediction than single-marker assays (AUC = 0.837).

CONCLUSIONS: This study has confirmed that combination assay of three markers to determine VEGF-C, MMP-9, and VEGF expression in circulation detects lymph node metastasis in NSCLC with higher accuracy than single-marker assays.