Angiogenesis and lymphangiogenesis of skin cancers.

Malignant melanomas of the skin are distinguished by their propensity for early metastatic spread by way of lymphatic vessels to regional lymph nodes; lymph node metastasis is a major determinant for the staging and clinical management of melanoma. The importance of tumor-induced lymphangiogenesis for lymphatic melanoma spread is unclear, however. Recent experimental and clinical evidence strongly suggest that active lymphangiogenesis is induced by many tumor types, including cutaneous melanoma, and that it plays an important role in lymphatic tumor dissemination. The extent of tumor-associated lymphangiogenesis can serve as a powerful prognostic tool for the evaluation of primary cutaneous melanomas. A better molecular understanding of the lymphatic system may provide new insights into the biology of tumor metastasis and may provide novel prognostic and therapeutic tools in metastatic disease.