Distant metastasis in breast cancer: molecular mechanisms and therapeutic targets.

Distant metastasis is responsible for the death of nearly 45,000 women per year in the US alone. At present, we have no clear understanding about the genetic events that govern the ability of breast cancer cells to settle at and colonize in specific sites in the body. This information is critical for developing therapeutic strategies that would target the tumor cells and their supporting environment at distant sites. This review will discuss investigations on 1) the steps of the metastatic pathway, 2) innovative technologies such as radiologic imaging and molecular manipulations of cells that would help us to study metastasis in real time, 3) strengths and weaknesses of current models for studying metastasis, and 4) how best to design large comprehensive gene searches during metastatic progression of breast cancer. These advances will enable the development of therapies targeted towards blocking the outgrowth of metastatic cells.