Epithelial cells in bone marrow of breast cancer patients at time of primary surgery: Clinical outcome during long-term follow-up

Purpose: To evaluate the detection of epithelial cells in bone marrow of br east cancer patients as an indicator of metastatic disease. Patients and Methods: Between 1989 and 1994, bone marrow biopsies were perf ormed on 393 breast cancer patients during primary surgery. Specimens were stained immunocytochemically for epithelial cells expressing cytokeratins o r the epithelial membrane antigen. The long-term outcomes of these patients were analyzed in this study. Results: In 166 of 393 patients, epithelial cells were found in bone marrow (BM) aspirates. These patients were designated BM+. The rate of tumor recu rrence or cancer-related death was significantly higher in BM+ patients tha n in BM- patients. Multivariate analysis using the Cox regression model rev ealed BM status as a prognostic parameter independent of tumor size and axi llary lymph node status. However, tumor size and axillary lymph node status were clearly superior prognostic parameters. Conclusion: Disseminated epithelial cells in BM are associated with poor cl inical outcome in breast cancer patients. However, the presence of these ce lls is not a sufficient parameter to predict growing metastases in the majo rity of patients, suggesting that epithelial cells in the BM of breast canc er patients at the time of surgery have limited metastatic potential. The r ole of these cells needs to be further evaluated. J Clin Oncol 19:3669-3674. (C) 2001 by American Society of Clinical Oncolog y.