CEA-, Her2/neu-, BCRP- and Hsp27-positive microparticles in breast cancer patients.

This is the first prospective case-control study that evaluates the expression of tumour-specific antigens on circulating microparticles (MP) in breast cancer patients and in women with benign breast tumour.,MP were determined by flow cytometry in patients with breast cancer (n=34; T1 (n=19) and T2 (n=15)) and women with benign breast tumour (n=19).,Patients with lymph node metastases (N1, n=9) showed significantly higher numbers of annexin V(+) MP (p=0.042), CD66(+) MP (p=0.045), BCRP1(+) MP (breast cancer resistance protein) (p=0.025) and Hsp27(+) MP (p=0.034) than controls. Furthermore, T1 patients had significantly higher levels of annexin V(+) MP (p=0.004), CD66(+) MP (p=0.025), BCRP1(+) MP (p=0.008) and Hsp27(+) MP (p=0.02) than controls.,Significant differences are present between breast cancer patients with lymph node metastases and controls concerning annexin V-, CD66-, BCRP1- and Hsp27-positive MP. To specify the role of these MP subpopulations in breast cancer progression, further studies enrolling larger patient groups are part of ongoing research.