Background: Lymph node metastasis is the most important factor to consider when deciding on the modality of resection in patients with early gastric cancer. The aim of the present study was to assess the relationship between preoperative serum angiopoietin-2, a lymphangiogenic growth factor, and lymph node metastasis in patients with early gastric cancer.
Methods: A total of 62 preoperative serum samples from patients diagnosed with early gastric adenocarcinoma, and 30 serum samples from healthy donors were obtained. The serum levels of angiopoietin-2 (Ang-2) were quantified by immunoassay. Intra- and peritumor lymphatic vessel density (I-LVD and P-LVD) were counted after immunohistochemical staining. The relationship between the serum Ang-2 levels and other prognostic variables (tumor size, histological type, depth of tumor invasion, I-LDV, P-LDV, presence of lymph node involvement, and distant metastasis) were then examined by univariate and multivariate linear regression analyses.
Results: The median serum levels of Ang-2 in patients were higher than those of healthy controls [311.1 ng/mL, interquartile range (IQR) 256.7-311.1 ng/mL versus 286.5 ng/mL, IQR 226.9-286.5 ng/mL; Mann-Whitney test, P = 0.016]. Eight patients had metastatic lymph nodes; the Ang-2 levels from the patients with metastatic lymph nodes were higher than from those with negative lymph nodes (297.5 ng/mL, IQR 251.1-385.8 ng/mL versus 416.0 ng/mL, IQR 337.1-485.5 ng/mL; Mann-Whitney test, P = 0.019). Elevated serum Ang-2 levels were associated with positive lymph node involvement and this finding was significant on univariate (P = 0.008) and multivariate logistic regression analysis (P = 0.011).
Conclusion: Serum Ang-2 levels were clinically useful markers for lymph node metastasis in patients with early gastric cancer.