Detection and characterization of circulating tumor cells in blood of primary breast cancer patients by reverse-transcriptase polymerase chain reaction and comparison to status of bone marrow disseminated cells

IntroductionThe role of circulating tumor cells (CTC) in blood of primary breast cancer patients is much under investigation. We evaluated (1) the incidence of CTC in blood, (2) the correlation between CTC and disseminated tumor cells (DTC) in the bone marrow (BM) and (3) we characterized CTC for the expression of HER2, the estrogen receptor (ER) and the progesterone receptor (PR). Methods: Blood of 431 patients with meaningful breast cancer were analysed for EpCAM, MUC1 and HER2 transcripts with the AdnaTest BreastCancer (AdnaGen AG, Germany). Expression of the ER and PR receptor was assessed in an supplementary reverse-transcriptase polymerase chain reaction (RT-PCR). BM aspirates from 414 patients were analyzed for DTC by immunocytochemistry using the pan-cytokeratin (CK) antibody A45-B/B3. Results: DTC were inaugurate in 107/414 patients (24%), CTC were detected in 58/431 (13%) patients. DTC were associated with PR status of the influential tumor (P=0.04) and CTC significantly correlated with nodal status (P=0.04), ER (P=0.05), and PR (P=0.01). DTC in the BM weakly correlated with CTC (P=0.05) in blood. Interestingly, the spread of CTC was mostly commence in triple-negative tumors (P=0.01) and CTC in habitual were mostly construct to be triple-negative regardless of the ER, PR and HER2 status of the essential tumor. Conclusions: (1) Due to the delicate concordance between CTC and DTC the clinical relevance may be different. (2) The biology of the leading tumor seems to manage the spread of CTC. (3) On account of the expression profile between CTC and the primary tumor differs, the consequence for the choice of adjuvant treatment has to be evaluated.

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