Expression pattern of vascular endothelial growth factor-C in human colorectal normal mucosa and neoplastic mucosa

BACKGROUND/AIMS: Vascular endothelial growth factor-C (VEGF-C) is a potent growth factor stimulating lymphangiogenesis. METHODOLOGY: We examined the expression of VEGF-C immunohistochemically in neoplastic as well as normal mucosa of colorectal tissues, and evaluated the significance of VEGF-C in colorectal carcinogenesis and as a marker to predict the outcome of colorectal cancer. RESULTS: VEGF-C was strongly stained in 70/79 adenomas (89%), but the staining was focal in all cases, and the expression pattern in adenomas was not significantly related to either dysplasia or size of the adenoma. In the 8/8 intramucosal carcinomas within adenomas, both the carcinomatous and adenomatous lesions were stained focally, but in 6 cases (75%), the VEGF-C-positive area was larger in the carcinomatous lesion than in the adenomatous lesion. In most invasive adenocarcinomas, VEGF-C was clearly stained (83/85; 98%), with both a focal (40%) and diffuse (60%) staining pattern. In invasive carcinomas, the expression of VEGF-C was significantly correlated with lymphatic involvement, lymph node metastasis and tumor size, but not with venous involvement or liver metastasis. Survival rate tended to be lower in the high VEGF-C group than in the low group, although statistical significance was not observed. CONCLUSIONS: These results suggest that VEGF-C plays a positive role in lymphatic spread in colorectal carcinomas.