[Cancer lymphangiogenesis and its role in metastasic dissemination]

It is well-known that there are different tumor-type-dependent metastatic patterns. For example, in carcinomas metastatic spread is preferentially via the lymphatic system by which they reach regional lymph nodes through pre-existent afferent lymph vessels and/or newly formed lymph capillaries; while in sarcomas the favored pathway is through bloodvessels. These metastatic patterns have been used for many years by clinicians and surgeons for staging and tumor resection, particularly in the case of breast cancer. Recently this knowledge has been applied to detection and resection of sentinel lymph nodes. The lymphatic system drains the interstitial fluid from tissues and reincorporates it into the blood flow; in addition, it forms part of the host's immune defense and in pathological conditions, induces different types of lymph edema and participates in tumor invasion and metastasis. Although, the study of lymphangiogenesis was stagnated for several decades, it was not until a few years ago that biomolecular mechanisms were discovered and many specific markers are now in use to study the process of tumor dissemination and metastasis. There is a tendency to utilize molecular knowledge in clinical settings for grading and estimating prognostic significance of tumors as well as to develop specific therapeutic strategies.