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Prognostic significance of vascular endothelial growth factor expression and microvessel density in carcinoma of ampulla of Vater.

BACKGROUND/AIMS
To investigate whether the expression of vascular endothelial growth factor (VEGF) and microvessel density (MVD) are of prognostic significance in ampullary carcinoma.


METHODOLOGY
Twenty-two resected tumor specimens from patients with ampullary carcinoma were immunohistochemically stained for VEGF and CD34 (surrogate for vessels) by streptavidin-peroxidase method.


RESULTS
Expression of VEGF in tumor tissue was found in 50% of patients. The mean MVD for entire group was 26.4 +/- 12.8. A significantly higher MVD was observed in the tumors with positive VEGF expression (35.0 +/- 9.6) compared with that of negative VEGF expression (17.7 +/- 9.3) (p<0.01). The expression of VEGF and MVD were closely related lymph node status and tumor TNM stage. The positive expression rate of VEGF and the average MVD in patients with lymph node metastases were 85.7% and 33.1 +/- 10.8 respectively, which were significantly higher than those in patients without lymph node metastases (33.3% and 22.8 +/- 11.8 respectively) (p<0.05). The positive expression rate of VEGF and the average MVD in patients with stage III and were 75% and 36.3 +/- 8.4 respectively, which were significantly higher than those in patients with stage I (25% and 18.4 +/- 10.1 respectively) or stage II (50% and 23.8 +/- 13.4 respectively) (p<0.05). The Kaplan-Meier survival curves showed that the 3-year survival rate for patients with positive VEGF expression or a high MVD (9.1% and 10% respectively) were lower than those in patients with negative VEGF expression or a low MVD (63.64% and 58.33% respectively) (p<0.05).


CONCLUSIONS
VEGF is positively correlated with MVD in ampullary carcinoma. VEGF and angiogenesis may play an important role in lymph node metastasis and progression of ampullary carcinoma. VEGF and MVD appear to be important prognostic predictor in patients with ampullary carcinoma.