Isolation of Circulating Tumor Cells in Patients with Thyroid Cancer

We report the feasibility of a workflow for CTC identification patients with cytological diagnosis of thyroid cancer involving an unbiased enrichment of tumor cells on the basis of size and deformability and subsequent CTC identification based on cell morphology and expression of specific markers [8]. Our method provides the possibility of recovering pure single or pooled cells by dielectrophoresis. With this approach we could identify a high number of CTCs in a single Thy5 patient. CTCs had been detected previously in metastatic patients affected by medullary thyroid carcinoma [9] by CellSearch, but the same approach on the whole failed to identify CTCs in patients affected by differentiated thyroid carcinoma. This could be due to the main drawback of CellSearch system which is represented by the fact that cells are selected a priori on the basis of EpCAM expression. Other authors reported low or undetectable expression of EpCAM in thyroid cancer [8]. On the contrary an enrichment step based on physical properties of CTCs, such as size and deformability, enables the capture of a heterogeneous population of CTCs, more representative of the disease complexity. Moreover, our workflow allows the recovery of a population of pure CTCs for downstream analysis, which is not feasible by CellSearch or flow cytometry.