100IN - The potential of circulating tumour cells as a liquid biopsy to guide therapy in prostate cancer

Date 27 September 2014
Event ESMO 2014
Session Liquid biopsy: Monitoring tumour-derived cell-free DNA, circulating tumour cells (CTC) and exosomes in patients with solid tumours
Topics Prostate Cancer
Translational Research
Presenter Klaus Pantel
Citation Annals of Oncology (2014) 25 (suppl_4): iv36-iv36. 10.1093/annonc/mdu312
Authors K. Pantel
  • -, UKE Universitätsklinikum Hamburg-Eppendorf KMTZ, - - Hamburg/DE

Abstract

Body

Abstract:

Sensitive methods have been developed to capture circulating tumor cells (CTCs) in the peripheral blood at the single cell level in prostate cancer patients (Pantel et al., Nature Rev Cancer 2008; Kang & Pantel, Cancer Cell 2013). CTCs are usually detected by immunostaining or RT-PCR assays, and more recently by the EPISPOT assay which measures the number of cells releasing/secreting tumor-associated marker proteins. Interestingly, detection of cell-free nucleic acids released by tumor cells such as tumor-associated DNA or microRNAs into the blood might become an indirect way to detect micrometastatic disease (Schwarzenbach/Pantel et al, Nature Rev Cancer 2011 & Nature Rev. Clin. Oncol. 2014). At present, most CTC assays rely on epithelial markers and miss CTCs undergoing an epithelial-mesenchymal transition (EMT). New markers such as the actin bundling protein plastin-3 (Yokobori et al., Cancer Res. 2013) are not downregulated during EMT and not expressed in normal blood cells might overcome this important limitation and, therefore, increase the sensitivity of CTC assays. Recently, in vivo capture of CTCs with an antibody-coated wire placed into the peripheral arm vein has become feasible and allows now the capture for CTCs from approx. 1.5 liters of blood within 30 minutes. CTC enumeration and characterization with certified systems provides reliable information on prognosis and may serve as liquid biopsy (Alix-Panabieres & Pantel, Clin. Chem. 2013; Pantel & Alix-Panabieres, Cancer Res., 2013). Moreover, monitoring of CTCs before, during and after systemic therapy (e.g., chemotherapy, hormonal therapy, antibody therapy) might provide unique information for the future clinical management of the individual prostate cancer patient and might serve as surrogate marker for response to therapy. Besides CTCs the analysis of ctDNA and circulating microRNAs may provide complementary information as “liquid biopsy” (Pantel & Alix-Panabieres, Cancer Res., 2013; Pantel et al., Nature Med. 2013; Heitzer et al., Genome Med. 2013; Schwarzenbach et al., Nature Rev. Clini. Oncol., 2014). This information can be used as companion diagnostics to improve the stratification of therapies and to obtain insights into therapy-induced selection of cancer cells (Wan, Pantel, Kang, Nature Med. 2013).

Disclosure:

The author has declared no conflicts of interest.