Vascular endothelial growth factor-A and -C: expression and correlations with lymphatic metastasis and prognosis in colorectal cancer.

Previous studies obtained contradicting results regarding the correlation between expression of VEGF-A, VEGF-C and colorectal cancer patients' clinicopathological features and prognosis. Moreover, the association between the growth factors' expression and lymphatic vessel invasion (LVI) with intratumoral and peritumoral difference has not been reported. In this study, 81 primary colorectal cancer samples were immunohistochemically stained for VEGF-A, VEGF-C and podoplanin. The expression of VEGF-A and VEGF-C in marginal portion was significantly higher than those in central portion (P = 0.000 for both). The expression of VEGF-A in marginal portion was correlated with lymph node metastasis (P = 0.031). The expression of VEGF-C in marginal portion was correlated with TNM stage (P = 0.045), peritumoral LVI (P = 0.048) and lymph node metastasis (P = 0.019). The group with high VEGF-A expression in marginal portion showed worse survival than the low expression group (P = 0.039). Patients with high expression of VEGF-C in the marginal portion were not significantly different from those with low VEGF-C expression (P = 0.121). Patients with high expression of both VEGF-A and VEGF-C in the marginal portion showed the worst survival (P = 0.015). In conclusion, increased expression of VEGF-A and VEGF-C in marginal portion of colorectal cancer was correlated with lymph node metastasis. VEGF-C facilitates colorectal cancer cells invade into peritumoral lymphatic vessels, and different mechanisms may exist in the invasion of tumor cells into peritumoral and intratumoral lymphatic vessels. Assessment the expression of both VEGF-A and VEGF-C in the marginal portion of tumor may help to identify patients with colorectal cancer with unfavourable overall survival.