Expression of vascular endothelial growth factor can predict distant metastasis and disease-free survival for clinical stage III rectal cancer following 30-Gy/10-f preoperative radiotherapy

Purpose The purpose of this study was to analyze the prognostic value of vascular endothelial growth factor (VEGF) in patients with stage III rectal cancer treated with 30-Gy/10-fraction (f) preoperative radiotherapy and radical surgery. Methods One hundred and sixteen patients with clinical stage III rectal cancer were studied. All patients underwent radical surgery after 30-Gy/10-f preoperative radiotherapy. Immunohistochemical examination of VEGF was performed on the resected 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 that this biomarker was associated with patient outcomes. Results The expression of VEGF was identified among 74.1 % (86 of 116) of patients. We found an increased incidence of distant metastasis (19.8 vs. 3.3 %, p = 0.039) and a decreased 3-year disease-free survival rate (96.7 % vs. 72.7 %, p = 0.003) in patients with positive VEGF staining. In multivariate survival analysis, positive VEGF staining (hazard ratio (HR) = 9.364, 95 % confidence interval (CI) 1.298-71.519, p = 0.027) and ypN+ stage (HR = 2.714, 95 % CI 1.419-3.331, p = 0.000) were the independent prognostic factors for disease-free survival. Subgroup analyses showed that the expression of VEGF was significantly associated with increased distant metastasis rate and decreased DFS in patients with ypN+ stage. Conclusions VEGF expression may have potential value for predicting distant metastasis and disease-free survival in stage III rectal cancer after 30-Gy/10-f preoperative radiotherapy. Inhibition of VEGF in combination with radiotherapy may improve the patient outcomes.