Comparative analysis of bone marrow micrometastases with sentinel lymph node status in early-stage breast cancer.

Abstract

570 Background: A definitive relationship between bone marrow (BM) micrometastases (M) and sentinel lymph node (SLN) status has not been established in Breast Cancer (BRCa). Hence, a retrospective study was done to examine the relationship between BMM and SLN status in BRCa patients (pts). Methods: T1/T2 BRCa pts underwent SLN biopsy and definitive surgery for primary tumors. At the operation, BM aspiration from bilateral post-superior iliac spines was performed. BM samples were examined using a Cytokeratin Detection Kit using CAM 5.2 monoclonal antibody and visualization achieved with a Ventana iView V-Red detection system. An Automated Cellular Imaging System was applied to identify metastatic BRCa cells. Pts with +ve BM underwent repeat BM analysis 6 months after completing initial treatments. Data was collected for T-stages, SLN, BM, ER/PR receptor and Her-2/neu statuses and analyzed using Chi-Square Analysis or Fischer’s Exact Test. Results: We analyzed 458 consecutive pts, of which SLN metastasesv(mets) were detected in 22.9% and BMM were detected in 8.1%. BMM were found 23% bilaterally and 77% unilaterally. BMM were detected in 11.4% of SLN +ve pts versus 7.1% of SLN -ve ptsv(p=0.15) and 6.8% of T1 pts versus 12.3% of T2 ptsvv(p=0.07). BMM were found in 8.7% of ER/PR +ve pts versus 4.5% of ER/PR –ve ptsvv(p=0.1) and 9.5% of HER2/neu +ve pts versus 7.7% of HER2/neu –ve ptsv (p=0.5) (Table). Repeat BM analysis detected BMM only in 6.6% pts. Conclusions: Bilateral BM aspirate resulted in a significant increase in detection of micrometastases. BM metastases may occur independently of lymphatic metastasis. Therefore, evaluation for the presence of BMM may help identify high risk pts with node negative disease in early stage BRCa. [Table: see text]