Cancer Metastases to the Liver: Mechanisms of Tumor Cell Colonization.

The liver is one of the most common sites for metastasis, which involves the spread from primary tumors to surrounding organs and tissues in the human body. There are a few steps in cancer expansion: invasion, inflammatory processes allowing the hepatic niche to be created, adhesions to ECM, neovascularization, and secretion of enzymes. The spread of tumor cells depends on the microenvironment created by the contribution of many biomolecules, including proteolytic enzymes, cytokines, growth factors, and cell adhesion molecules that enable tumor cells to interact with the microenvironment.