Abstract: BACKGROUND ＆ AIM： To study the expression of vascular endothelial growth factor C (VEGF-C) and Fms-like tyrosine kinase 4(Flt-4) in non-small cell lung cancer (NSCLC) and the clinical significance. MATERIALS AND METHODS: Detection of VEGF-C and its receptor Flt-4 by RT-PCR in 12 paracancer tissues and 40 NSCLC cases and by Strept avidin-biotin peroxidase(S-P) immunohistochemical staining in 10 paracancer tissues, 60 NSCLC cases and 32 metastaticlymph nodes of NSCLC. RESULTS：RT-PCR detection result：the relative contents of VEGF-C mRNA and Flt-4 mRNA in NSCLC were higher than that in paracancer tissues and had positive correlation with lymph node metastasis. The expression of VEGF-CmRNA had positive correlation with tumor TNM stage. S-P detection result：The difference of positive expression rate of VEGF-C and Flt-4 in NSCLC and paracancer tissues and lymphatic node metastasis was significant respectively. The expression of VEGF-C of NSCLC correlated with the TNM stages. The expression of VEGF-C and Flt4 of NSCLC was closely related to lymph node metastasis. VEGF-C,Flt-4 had no relation with the histological type and pathologic grade. The microvessels of positive Flt-4 in lymphatic node with metastasis were higher than that in lymphatic node without metastasis. The difference was significant. CONCLUSIONS: VEGF-C, secreted by lung cancer cells, up-regulates the expression of Flt-4 in NSCLC and takes its effect via Flt-4 receptors in cell membrane by autocrine. It contributes to the genesis of NSCLC. Expression of VEGF-C can serve as the indication of lymphatic metastasis in lung cancer.

Key words: non-small-cell lung cancer, lymphotic metastasis, endothelial growth factor