Disseminated cancer cells in bone marrow of breast cancer patients have putative cancer stem cell phenotype

Tumor cell dissemination to bone marrow is an early event in progression of breast cancer and is associated with poor prognosis. Disseminated tumor cells (DTC) are easily detected by immunohistochemistry for epithelial antigens , such as cytokeratins (CK). However, the biology of these cells is not well understood and is critical for ther-