Circulating tumor cells in early breast cancer: A connection with vascular invasion

Although circulating tumor cells (CTCs) have been studied in early breast cancer (EBC), their value in this setting is still not fully understood. We isolated and studied CTCs in the peripheral blood (PB) of 48 EBC patients pre-surgery and one and 6 months post-surgery using an approach involving EpCAM-independent enrichment and a dielectrophoresis-based device. Method feasibility and the correlation between CTCs and primary tumor features were evaluated. CTCs were found in 27.1% of pre-surgery patients, 20.9% of patients one-month post-surgery, and about 33% of patients 6-months post-surgery. CTCs were recovered singly for further molecular characterization. Pre-surgery CTC-positive patients more frequently had negative prognostic features, i.e. high proliferation, large tumor dimension, lymph node positivity and negative receptor status than the other subgroup. In particular, vascular invasion showed a statistically significant correlation with CTC-positivity. Our procedure proved feasible and capable of recovering CTCs from EBC patients. Furthermore, our results suggest that CTCs may be linked to vascular invasion and to other known negative prognostic factors.