The biology of colorectal cancer metastasis.

Metastasis is a complex process involving a series of tumor-host interactions that follow tumor initiation and progression. Metastatic cancer cells must be capable of completing all stages of this process to establish secondary foci at distant sites. Most studies infer the functional significance of various observations based on models designed to emphasize the contributions of single molecules or ligand-receptor pairs. While providing useful insights into potential mechanisms of tumorigenesis and metastasis, additional studies are needed to elucidate the complex dynamic interactions involved in these processes. Nonetheless, a better understanding of how tumor cells metastasize is leading to new therapies to prevent and treat micrometastatic disease.