The expression of vascular endothelial growth factor determines the efficacy of post-operative adjuvant chemotherapy using oral fluoropyrimidines in stage II or III colorectal cancer.

The aim of this study was to determine any correlation between the efficacy of post-operative adjuvant chemotherapy using oral fluoropyrimidines and the vascular endothelial growth factor (VEGF) expression in primary colorectal cancer tissues. The data were reviewed retrospectively on 342 patients with colorectal cancer at stage II or III, who underwent potentially curative resection between 1988 and 1998. Of these, 225 received post-operative administration of oral fluoropyrimidines such as UFT and 5'-DFUR, while the other 117 patients underwent surgery alone. Immunostaining for VEGF was performed using colorectal tumours. Overall, VEGF was positively expressed in primary tumour cells in 48% of patients. The disease-free survival rate and the overall survival rate in the chemotherapy group were higher than those in the surgery-alone group, although not significantly. However, the disease-free survival rate and the overall survival rate were similar between the two groups in patients with a tumour positive for VEGF. Multivariate analysis revealed that the VEGF expression was an independent factor for post-operative recurrence, and the VEGF expression and post-operative adjuvant chemotherapy were an independent factor for overall survival, in addition to the lymph node metastasis and the venous invasion. In conclusion, the efficacy of post-operative adjuvant chemotherapy using oral fluoropyrimidines may not be as great for patients with a tumour positive for VEGF having a greater risk of post-operative recurrence. The results support further investigation on efficacy of molecular targeting therapy for VEGF in combination with oral fluoropyrimidines as post-operative adjuvant therapy in colorectal cancer positive for VEGF.