IMMUNODETECTION OF BREAST-CANCER CELLS IN BONE-MARROW FOR MONITORING HIGH-DOSE SEQUENTIAL CHEMOTHERAPY

The immunodetection of breast-cancer cells in bone marrow may be a use ful technique for monitoring the efficiency of chemotherapy in selecte d clinical settings. We used monoclonal antibodies against cytokeratin s and an epithelial membrane antigen pool to detect microscopic metast atic deposits in bone marrow aspirates from a high-risk patient before and after high-dose sequential chemotherapy. In the slides done befor e therapy, 250 immunostained cells were found, but only 20 immunostain ed cells were found in slides made after chemotherapy. Moreover, doubl e-staining procedures showed consistent colocalization of the two mark ers on the same cancer cells. A fraction of the micrometastatic cells were additionally immunostained for Ki-67, a well-established marker o f cell proliferation. These data suggest that the immunodetection of b reast cancer cells in bone marrow may have potential clinical implicat ions in the management of high-risk breast cancer.