44P - Gene expression of breast cancer related genes in circulating tumour cells (CTCs) from patients with metastatic breast cancer

Date 07 May 2015
Event IMPAKT 2015
Session Welcome reception and Poster Walk
Topics Breast Cancer, Metastatic
Pathology/Molecular Biology
Translational Research
Presenter Kristina Aaltonen
Citation Annals of Oncology (2015) 26 (suppl_3): 15-24. 10.1093/annonc/mdv117
Authors K.E. Aaltonen1, C. Graffman2, A. Larsson1, L. Rydén3
  • 1Department Of Clinical Sciences, Oncology, Lund University, SE-22381 - Lund/SE
  • 2Skåne Department Of Oncology, Skane University Hospital-Lund, SE-22385 - Lund/SE
  • 3Department Of Surgery, Skane University Hospital-Lund, SE-22381 - Lund/SE

Abstract

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Introduction: Detection of circulating tumour cells (CTCs) in peripheral blood has an established prognostic significance in patients with metastatic breast cancer. Change in the number of detected CTCs is also an indication of response to therapy. Characterisation of CTCs could provide easily accessible treatment predictive information of present cancer cells within the patient and could reveal important knowledge about the metastatic process. The aim of this pilot study was to characterize CTCs with regard to both treatment predictive and more experimental markers by analysing the expression of genes associated with breast cancer.

Methods: Blood samples from twelve patients with metastatic breast cancer included in the ongoing CTC-MBC study at Lund University, Sweden (Clinical Trials Id. NCT01322893) were analysed in this pilot study. Systemic treatment included endocrine, targeted and chemotherapy regimen. Blood samples were collected before start of 1st line therapy and at four time points. If progression occurred, a new round of samples was taken. CTCs were isolated from whole blood using the commercial kits AdnaTest EMT1/stem cell and AdnaTest EMT2/stem cell (AdnaGen AG, Langenhagen, Germany). With this method, CTCs are captured using antibodies directed against EpCAM and MUC-1 (EMT1-kit) or EpCAM, HER2 and EGFR (EMT2-kit). Gene expression analyses from CTCs at each time point was performed by TATAA Biocenter (Gothenburg, Sweden) using qPCR. 38 breast cancer related genes were analysed including the oestrogen receptor (ESR), HER2, VEGFR2, ALDH1, PI3K, PTEN and TWIST1.

Results: Using positive expression of pseudo-markers EpCAM, MUC1 and HER2 as definition of CTCs, 6 of 12 patients were positive for CTCs. However, gene expression of additional markers in potential CTCs suggests complex patterns such as an increase in TWIST1, ALDH1 and SATB1 at time of progression.

Conclusions: We present gene expression data from CTCs isolated before and during therapy in metastatic breast cancer patients. This type of characterisation could provide information of importance for treatment response and clinical outcome.

Clinical trial identification: NCT01322893, March 24 2011

Disclosure: All authors have declared no conflicts of interest.