Resting and activated endothelial cells are increased in the peripheral blood of cancer patients

Circulating endothelial cells (CECs) were enumerated in 20 healthy controls and 76 newly diagnosed cancer patients by means of a-color flow cytometry. In breast cancer (n = 46) and lymphoma (n = 30) patients, both resting and activated CECs were increased by 5-fold (P < .0008 vs control). CECs signi ficantly correlated with plasma levels of vascular cell adhesion molecule-1 and vascular endothelial growth factor. Resting and activated CECs were si milar to healthy controls in 7 lymphoma patients achieving complete remissi on after chemotherapy, and activated CECs were found to decrease in 13 brea st cancer patients evaluated before and 24 hours after quadrantectomy.