Comparative analysis of bone marrow (BM) micrometastasis (M) with sentinel lymph node (SLN) status in early breast cancer (BRCa)

508 Background: While sentinel lymph node (SLN) metastasis (mets) and bone marrow (BM) micrometastases (M) provide prognostic information in breast cancer (BRCa) patients (pts), a definitive relationship between the two has not yet been proven. We hypothesize that the presence of BMM may not infer an increased risk of SLN mets due to differences in their mechanisms of spread. Methods: We conducted a 6-year retrospective study of 251 T1/T2 BRCa pts who underwent bilateral iliac crest bone marrow aspiration, SLN mapping, and either lumpectomy, partial mastectomy, modified radical mastectomy, or total mastectomy by a single surgeon. BM samples were examined for micrometastases by Automated Cellular Imaging System using Chroma Vision Cytokeratin Detection Kit to detect cells expressing CK 8 as defined by CAM 5.2 monoclonal antibody. Pts with BMM underwent repeat BM analysis after completion of adjuvant chemotherapy. Data was collected for SLN, BM, ER/PR and HER2/neu status. Results: There were 251 consecutive...