Clinic Pathology Study on Expression of VEGF and VEGFR-2 in Rectal Cancer Treated with 30 Gy/10f Preoperative Radiotherapy

Objective To analyze the prognostic value of vascular endothelial growth factor (VEGF)and Vascular Endothelial Growth Factor Receptor-2(VEGFR-2) in patients with rectal cancer treated with 30 Gy/10 f preoperative radiotherapy and radical surgery. Methods One hundred and sixteen patients with clinical stage Ⅲ rectal cancer from Aug.2002 to Dec.2007 were studied.All patients underwent radical surgery after 30 Gy/10 f preoperative radiotherapy.Immunohistochemical examination of VEGF and VEGFR-2 were performed on the reselected tumor specimen.An immunohistochemical score established from the extension and intensity of the markers was used for analysis.The log rank test and proportional hazards regression analysis were used to calculate the probability of this biomarker associated with patients′ prognosis. Results The expressions of VEGF and VEGFR-2 were identified in 74.1% (86/116) and 42.2% (49/116) of patients.Univariate and multivariate analysis showed that lymph node metastasis (ypN stage) and positive VEGF expression were the independent risk factors for distant metastasis.Univariate analysis showed that positive expressions of VEGF and VEGFR-2,lymph node metastasis (ypN stage) and tumor invasion depth (ypT stage) were correlated with decreased 3-year disease-free survival rate (P<0.05).In multivariate survival analysis,positive VEGF staining and ypN+ stage were the independent prognostic factors for disease-free survival.Subgroup analyses showed the expression of VEGF was significantly associated with the increased distant metastasis rate and decreased DFS in patients with ypN+ stage. Conclusion VEGF expression may have potential value for predicting distant metastasis and disease-free survival in rectal cancer after 30 Gy/10 f preoperative radiotherapy.Inhibition of VEGF in combination with radiotherapy may improve the patients′ prognosis.