Detection of disseminated tumor cells in peripheral blood of patients with breast cancer: correlation to nodal status and occurrence of metastases Helge Taubert, a, * ,1 Karen Blu ¨mke, a,b,1 Udo Bilkenroth, a,1 Axel Meye, a,2 Andreas Kutz, a Frank Bartel, a,b Christine Lautenschla ¨ger, c Eva Johanna Ulbrich, d Norbert Nass, d Hans-Ju ¨rgen Holzhausen, a Heinz Koelbl, d and Antje Lebrecht d a Institute of Pathology, Martin-Luther University of Halle-Wittenberg, Halle, Germany b Department of Urology, Martin-Luther University of Halle-Wittenberg, Halle, Germany c Institute of Medical Epidemiology, Biometry and Medical Informatics, Martin-Luther University of Halle-Wittenberg, Halle, Germany d Department of Gynecology, Martin-Luther University of Halle-Wittenberg, Halle, Germany Received 6 June 2003 Abstract Objective. Soon after breast cancer becomes invasive, it sheds cancer cells into the blood stream or the cancer cells are spread via lymphatic vessels. The early and unambiguous detection of these disseminated tumor cells (DTC) is of importance for the evaluation of the tumor process and for monitoring therapy response. The detection of disseminated tumor cells by immunocytochemistry (ICC) without previously performing tumor cell enrichment is time consuming and may miss a considerable part of these cells. Therefore, we have applied a negative immunomagnetic enrichment of disseminated tumor cells from the peripheral blood of patients with breast cancer by the depletion of CD45 + leukocytes using automated magnetic activated cell separation (autoMACS). Methods. One hundred twenty-five blood samples from 83 breast cancer patients were investigated for occurrence of disseminated tumor cells by autoMACS technique and immunocytochemical cytokeratin staining. Frequency of disseminated tumor cells was analyzed statistically for correlation to clinical data. Results. Thirty-three of the 125 blood samples (26%) originating from 29 of 83 breast cancer patients (35%) carried cytokeratin positive (CK + ) tumor cells. The occurrence of CK + tumor cells correlated significantly with the nodal status ( P = 0.009) and with the occurrence of metastases at the time of primary tumor resection ( P = 0.003). Conclusions. The finding that occurrence DTC detected in peripheral blood of breast cancer patients correlated with nodal stage and metastases is described for the first time. It suggests that disseminated tumor cells identified in peripheral blood by autoMACS are associated with tumor characteristics of breast cancer. D 2003 Elsevier Inc. All rights reserved. Keywords: Disseminated tumor cells; Magnetic activated cell separation; AutoMACS; Breast cancer; Cytokeratin expression; Detection of minimal residual disease Introduction Cancer-related death from breast cancer is mainly caused by the occurrence of distant metastases. At the time of the primary breast cancer diagnosis, the majority of the affected patients have no evidence of metastatic disease determined by routine examinations using clinical, radiological, and biochemical procedures. However, breast cancer sheds can- cer cells into the blood stream or via lymphatic vessels soon after it becomes invasive, and they can persist for up to 20– 25 years [1]. Metastatic disease occurs within 5 years after tumor resection in about 50% of the cases with apparent 0090-8258/$ - see front matter D 2003 Elsevier Inc. All rights reserved. doi:10.1016/j.ygyno.2003.09.009 Abbreviations: Ab, antibody; CK, cytokeratin(s); DTC, disseminated tumor cells; ICC, immunocytochemistry; MACS, magnetic activated cell separation; MNC, mononuclear cells, sample(s). * Corresponding author. Institute of Pathology, Faculty of Medicine, Martin-Luther University of Halle-Wittenberg, Magdeburger Strasse 14, D-06097 Halle/Saale, Germany. Fax: +49-345-557-1295. E-mail address: helge.taubert@medizin.uni-halle.de (H. Taubert). 1 First three authors contributed equally to the manuscript. 2 Present address: Department of Urology, Technical University Dresden, Germany. www.elsevier.com/locate/ygyno Gynecologic Oncology 92 (2004) 256 – 261