Methods: In a prospective single center study, CTC were enumerated with the CellSearch system in 30 ml of
peripheral blood of 602 patients before undergoing surgery for breast cancer. There were 97 patients with a
benign tumor, 101 did not meet the inclusion criteria of which there were 48 patients with DCIS, leaving 404 stage
I to III patients. Patients were stratified into unfavorable (CTC ≥1) and favorable (CTC = 0) prognostic groups