Many previous studies have suggested that cyclooxygenase-2 (COX-2) over expression is closely related to angiogenesis. However, few have reported the relationship between COX-2 and lymphangiogenesis which is still unclear. The aim of this study was to determine the relationship between COX-2 expression and lymphangiogenetic factor, VEGF-C, in human gastric cancer and to correlate COX-2 and VEGF-C expression with other clinocopathological features to investigate whether COX-2 contributes to lymphangiogenesis and enhances lymph node metastasis.

One hundred patients who underwent curative radical surgery in Hanyang University hospital from July 1998 to June 2001 were selected. The expression of COX-2 and VEGF-C were detected by using immunohistochemistry, and the relationships between these two parameters and several clinicopathological factors (gender, stage, lymph node status, tumor location, Lauren classification and angioinvasion) were determined.

Increased COX-2 expression was found in 86 of 100 tumor samples (86%) and in 70 of 100 tumor samples (70%) with VEGF-C. A high correlation between VEGF-C expression and lymph node metastasis was observed (P=0.033) along as well as COX-2 expression (P=0.012). Also, there was a significant correlation between COX-2 and VEGF-C expression (P=0.026), yet no correlation were found between COX-2 and VEGF-C expression and other clinicopathological parameters.

Our study suggests that COX-2 expression contributes to lymphangiogenesis by mediating VEGF-C and finally promoting lymph node metastasis.