Circulating tumor cells in breast cancer at the diagnosis are associated with lymph node involvement, tumor size and negative ER status

We investigated the association of circulating tumor cells (CTC) with poor prognostic markers in breast cancer (BC) at time of diagnosis. Peripheral blood (PB) samples from 190 patients with invasive BC, 12 patients with in situ BC, before theraphy and/or surgery, and 330 from patients without BC were tested for CTCs by RT-PCR for human mammaglobin (hMAM). hMAM was expressed only in PB of invasive BC (9.5%) and a significant correlation was found between CTCs with lymph node involvement, tumour size and negative ER. We conclude that CTC detention in invasive BC may be an additional poor prognostic indicator.