Detection and management of bone marrow micrometastases in breast cancer

The presence and number of breast cancer micrometastases in the bone marrow at the time of diagnosis or initial treatment appear to predict early distant relapse. Immunologic techniques to detect such bone micrometastases, in combination with traditional prognostic variables, such as axillary lymph node status and tumor diameter, may allow for the identification of patients at high risk of systemic disease, who may benefit from adjuvant systemic chemotherapy. Immunofluorescent and immunochemical monoclonal antibody techniques have similar sensitivity in the detection of cancer cells in bone marrow. Future research is needed to develop more specific monoclonal antibodies and to determine the characteristics of the primary tumor that correlate with bone marrow micrometastasis, as well as the characteristics of micrometastases that correlate with recurrence.