Vascular endothelial growth factor expression predicts outcome and lymph node metastasis in squamous cell carcinoma of the esophagus.

Vascular endothelial growth factor (VEGF) expression and tumor microvessel density (MVD) were examined by immunohistochemical staining in 117 cases of thoracic esophageal squamous cell carcinoma. Thirty-six (31%) of the 117 cases were evaluated as VEGF-positive. The average number of metastatic lymph nodes at surgery was 5.6 in the VEGF-positive cases and 3.0 in the VEGF-negative cases and was significantly higher in those with VEGF-positive cases (P = 0.04). The incidence of pathological tumor (PT)2-4 cases among the high-MVD cases was significantly higher than among the low-MVD cases (P = 0.01). MVD was 59.4 +/- 4.7 (mean +/- SE)/mm2 in the VEGF-positive cases and 47.9 +/- 3.8/mm2 in the VEGF-negative cases. The MVD of the VEGF-positive tumors was higher than that of VEGF-negative tumors, but the difference was not significant (P = 0.08). The survival rate of the patients with high-MVD tumors was significantly poorer than those with low-MVD tumors, and the survival rate of those patients with VEGF-positive tumors was significantly poorer than in those with VEGF-negative tumors (P = 0.009 and P = 0.04, respectively). The cumulative survival rates in the VEGF-positive groups were found to be significantly poorer in the pT3 and pathological node (pN)1 groups when stratified according to pT factor (pathological T category) and pN factor (pathological N category) in the tumor-node-metastasis (TNM) classification. VEGF expression had the second highest hazard ratio in the multivariate analysis, after pN factor. These results indicate that VEGF is a useful marker for predicting the outcome in patients with more advanced esophageal squamous cell carcinoma. It seems that TNM factors and VEGF expression are important factors in the selection of appropriate treatments.