INTRODUCTION: This study analyzes peripheral blood samples from breast cancer (BC) patients. CTCs from peripheral blood were enriched by size-based separation and were then cultivated in vitro. The primary aim of this study was to demonstrate the antigen independent CTC separation method with high CTC recovery. Subsequently, CTCs enriched several times during the treatment were characterized molecularly. METHODS: Patients with different stages of BC (N = 167) were included into the study. All patients were candidates for surgery, surgical diagnostics, or were undergoing chemotherapy. In parallel, 20 patients were monitored regularly and in addition to CTC presence, also CTC character was examined by qPCR, with special focus on HER2 and ESR status. RESULTS: CTC positivity in the cohort was 76%. There was no significant difference between the tested groups, but the highest CTC occurrence was identified in the group undergoing surgery and similarly in the group before the start of neoadjuvant treatment. On the other hand, the lowest CTC frequencies were observed in the menopausal patient group (56%), ESR+ patient group (60%), and DCIS group (44.4%). It is worth noting that after completion of neoadjuvant therapy (NACT) CTCs were present in 77.7% of cases. On the other hand, patients under hormonal treatment were CTC positive only in 52% of cases. DISCUSSIONS: Interestingly, HER2 and ESR status of CTCs differs from the status of primary tumor. In 50% of patients HER2 status on CTCs changed not only from HER2+ to HER2-, but also from HER2- to HER2+ (33%). ESR status in CTCs changed only in one direction from ESR+ to ESR-. CONCLUSIONS: Data obtained from the present study suggest that BC is a heterogeneous disease but CTCs may be detected independently of the disease characteristics in 76% of patients at any time point during the course of the disease. This relatively high CTC occurrence in BC should be considered when planning the long-term patient monitoring.

• MeSH
• alfa receptor estrogenů genetika   MeSH
• dospělí MeSH
• genetická heterogenita * MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové biomarkery genetika   MeSH
• nádorové cirkulující buňky patologie   MeSH
• nádory prsu krev   genetika   patologie   MeSH
• receptor erbB-2 genetika   MeSH
• regulace genové exprese u nádorů MeSH
• senioři MeSH
• staging nádorů MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Resistance to systemic therapy is a major problem in metastatic breast cancer (MBC) that can be explained by initial tumor heterogeneity as well as by evolutionary changes during therapy and tumor progression. Circulating tumor cells (CTCs) detected in a liquid biopsy can be sampled and characterized repeatedly during therapy in order to monitor treatment response and disease progression.Our aim was to investigate how CTC derived gene expression of treatment predictive markers (ESR1/HER2) and other cancer associated markers changed in patient blood samples during six months of first-line systemic treatment for MBC. CTCs from 36 patients were enriched using CellSearch (Janssen Diagnostics) and AdnaTest (QIAGEN) before gene expression analysis was performed with a customized gene panel (TATAA Biocenter).Our results show that antibodies against HER2 and EGFR were valuable to isolate CTCs unidentified by CellSearch and possibly lacking EpCAM expression. Evaluation of patients with clinically different breast cancer subgroups demonstrated that gene expression of treatment predictive markers changed over time. This change was especially prominent for HER2 expression.In conclusion, we found that changed gene expression during first-line systemic therapy for MBC could be a possible explanation for treatment resistance. Characterization of CTCs at several time-points during therapy could be informative for treatment selection.

• MeSH
• chemorezistence MeSH
• dospělí MeSH
• Kaplanův-Meierův odhad MeSH
• lidé středního věku MeSH
• lidé MeSH
• metastázy nádorů MeSH
• nádorové biomarkery * MeSH
• nádorové cirkulující buňky metabolismus   patologie   MeSH
• nádory prsu genetika   patologie   terapie   MeSH
• progrese nemoci MeSH
• receptor erbB-2 genetika   MeSH
• receptory pro estrogeny genetika   MeSH
• regulace genové exprese u nádorů * MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• staging nádorů MeSH
• stanovení celkové genové exprese MeSH
• transkriptom MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

With the development of sophisticated individualized therapeutic approaches, the role of pathology in classification of tumors is enormously increasing. The solely morphological characterization of neoplastic process is no more sufficient for qualified decision on optimal therapeutic approach. Thus, morphologic diagnosis must be supplemented by molecular analysis of the lesion with emphasis on the detection of status of certain markers used as predictive factors for targeted therapy. Both intrinsic and acquired types of intratumor heterogeneity have an impact at various moments of cancer diagnostics and therapy. The primary heterogeneity of neoplastic tissue represents a significant problem in patients, where only limited biopsy samples from the primary tumor are available for diagnosis, such as core needle biopsy specimens in breast cancer, transthoracic or endobronchial biopsies in lung cancer, or endoscopic biopsies in gastric cancer. Detection of predictive markers may be influenced by this heterogeneity, and the marker detection may be falsely negative or (less probably) falsely positive. In addition, as these markers are often detected in the tissue samples from primary tumor, the differences between molecular features of the primary lesion and its metastases may be responsible for failure of systemic therapy in patients with discordant phenotype between primary and metastatic disease. The fact of tumor heterogeneity must be taken into consideration already in establishing pathological diagnosis. One has to be aware that limited biopsy specimen must not always be fully representative of the entire tumor volume. To overcome these limitations, there does not exist one single simple solution. Examination of more tissue (preference of surgical resection specimens over biopsies, whenever possible), use of ultra-sensitive methods able to identify the minute subclones as a source of possible resistance to treatment, and detection of secondary molecular events from the circulating tumor cells or circulating cell-free DNA are potential solutions how to handle this issue.

• MeSH
• DNA nádorová genetika   MeSH
• genetická heterogenita MeSH
• lidé MeSH
• molekulární patologie metody   MeSH
• nádorové biomarkery genetika   MeSH
• nádorové cirkulující buňky patologie   MeSH
• nádory diagnóza   genetika   patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH