Many studies have demonstrated the presence of increasing newly formed lymphatic vessels in tumour tissue, which is significantly correlated with the invasion of tumours,lymphatic metastasis, prognosis and so on. Re-cently,with the discovery of specific lymphatic endothelial cells markers and the development of novel experiment methods, turnout lymphangiogenesis become the focusing point for researchers. Here we will review what is known a-bout the reasons, molecular mechanisms and inhibitors of lymphangiogenesis in neoplasms.

Objective To investigate the involvement of VEGFR-3 signaling pathway in lymphatic metastasis of thyroid cancer. Methods The expression of VEGFR-3 mRNA in thyroid carcinoma and normal thyroid tissue was detected by RT-PCR. The expression of VEGFR-3 mRNA and the lymphatic vessel density (LVD) in thyroid carcinoma and normal thyroid tissue was measured by immunohistochemical staining. Results All thyroid cancer samples expressed VEGFR-3 and the expression rate of VEGFR-3 in thyroid carcinoma was significantly higher than that in the normal thyroid group ( P ＜ 0. 05 ). LVD in thyroid cancer was significantly higher than that in normal control. LVD with lymph nodes metastasis ( N + ) was significantly higher than that without lymph node metastasis (NO) (P ＜ 0. 05). Conclusions There is upregulatin of VEGFR-3 expression in thyroid carcinoma. The higher the expression of VEGFR-3, the severer of lymph node metastasis. VEGFR-3 receptor-mediated signal transduction pathway might be an important factor of thyroid cancer lymph node metastasis.