Chest CT and serum vascular endothelial growth factor-C level to diagnose lymph node metastasis in patients with primary non-small cell lung cancer.

STUDY OBJECTIVE: Accurate tumor staging is essential for choosing the appropriate treatment strategy for lung cancer. CT of the chest is the most commonly used noninvasive staging method of the lymph node metastasis, but it is far from satisfying. We evaluated whether circulating vascular endothelial growth factor (VEGF)-C could give additional information for diagnosing lymph node metastasis in patients with lung cancer.

PATIENTS AND METHOD: Serum samples were obtained from 116 patients with primary non-small cell lung cancer (NSCLC). All patients underwent preoperative CT of the thorax. Clinical T and N stages were compared to the final T and N stages obtained from pathologic findings. Serum VEGF-C concentration was assayed by commercially available sandwich enzyme-linked immunosorbent assay. We evaluated the utility of serum VEGF-C level as a marker for nodal metastasis comparing the utility of CT.

RESULTS: Preoperative and final T categories completely agreed in 82.8%. Regarding nodal metastasis, the accuracy of CT was 68.1%. Patients with lymph node metastasis showed higher serum VEGF-C concentrations than those without lymph node metastasis (p = 0.0007). Serum VEGF-C reached the highest sensitivity and specificity in diagnosing lymph node metastasis when a cut-off value of 1,850.6 pg/mL was applied (sensitivity, 70.0%; specificity, 77.3%). Serum VEGF-C visually correlated with CT scan in the detection of lymph node metastasis (sensitivity, 74.0%; specificity, 80.3%; positive predictive value, 74.0%; negative predictive value, 80.3%; accuracy, 77.6%). When the cases were limited to adenocarcinoma, better results could be obtained.

CONCLUSIONS: Serum VEGF-C is a reliable marker for lymph node metastasis in NSCLC. Serum VEGF-C evaluation and CT examination are complementary to each other for accurate lymph node staging in NSCLC.