Metastasis

Metastasis is the most dreaded aspect of the carcinogenic process. More than ninety percent of all cancer deaths are attributable to the consequences of the primary tumor successfully colonizing distant organs. Unlike the situation with colon cancer, a patient with breast cancer can never be considered 'cured', since as many as a third of breast cancer patients who have apparently curative surgery for their primary tumors ultimately relapse with metastatic disease, sometimes decades later. Much effort is now devoted to understanding this process of metastasis, and finding ways to predict and prevent its occurrence. This publication covers recent advances in the field, specifically as they relate to breast cancer. The availability of new tools and technological approaches has prompted a reconsideration of the very definition of a metastasis. Furthermore, a number of commonly held myths are being explored and a new definition of a metastasis, with important implications for clinical staging, is being proposed. Also, a novel conceptual framework for cancer progression based on the system-level dynamics of regulatory networks is presented and the role of chemokines in mediating some of the evolving transactional processes between tumor and stroma is being reviewed.