Metastasis

Metastasis is a complex sequence of processes that take place when a tumor cell exits the primary tumor, and establishes a secondary tumor by traveling to a distant site via the circulatory system. The complex process of metastasis depends on various components for successful dissemination and tumor cell growth at a secondary site. Metastatic processes include: (1) neoplastic progression, (2) angiogenesis, (3) migration and invasion, (4) intravasation, (5) circulation and embolism, (6) extravasation, and (7) metastatic tumor establishment in the target tissue. In this chapter we will discuss the steps involved in the complex process of tumor metastasis and the molecular mechanisms that underly each one of these steps.