Artikel
Tumor cell detection in peripheral blood of patients with primary lymph node negative breast cancer
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Veröffentlicht: | 20. März 2006 |
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Gliederung
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Background: The purpose of this study was detection and analysis of circulating tumor cells in blood of breast cancer patients by expression profiling using disseminated tumor cell (DTC) detection assay.
Material and Methods: 173 Patients with primary breast cancer are registrated in this clinical study. 96 of these patients were lymph node negative and 77 were lymph node positive. For DTC analysis five ml EDTA-blood were needed. The assay consists of immunomagnetic tumor cell selection (target antigens EpCAM and MUC-1). Preanalytically selected cells were used for mRNA-isolation and synthesis of c-DNA. Breast carcinoma-associated transcripts EpCAM (EP), MUC-1 (MU) and HER-2 (HE) were analysed by multiplex PCR. Claudin7 (C7) was determined by single-round RT-PCR, while cytokeratin 19 (CK), mammaglobin 1 (MG), prostate-specific ets factor (PSE) and survivin (SUR) were determined by nested RT-PCR. By capillary electrophoresis with the Agilent Bioanalyzer 2100 PCR products were analysed. Sensitivity for every single transcript was adjusted to two tumor cells per five ml blood.Examination of blood of healthy donors was expedient for the corroboration of the RT-PCR specificity.
Results: In the group of patients with lymph node negative breast cancer (n=96) we achieved an overall detection rate of 18 %. Tumor-associated transcripts were heterogeneously expressed in positive samples. The tumor-associated marker with the highest occurrence of 82% was MUC-1. 14% of the patients were positive for more than one of the markers (Table 1 [Tab. 1]).
Discussion: Recently microarray strategies confirmed established and identified new informative molecular markers for the detection of micrometastatic cancer cells. We have established a c-DNA bank of peripheral blood samples from patients with primary lymph node negative breast cancer. Tumor cells were enriched by a new immunobead technique. Eight informative markers were analysed by RT-PCR, resulting in an 18% detection rate. The patients of this study group will be followed up at three months intervals to determine the clinical relevance of these results. DTC might be prognostic indicators of tumor progression and consequently may allow improvement of individual patient outcome prediction.