Circulating microRNAs as blood-based markers for patients with primary and metastatic breast cancer.
BACKGROUND
MicroRNAs (miRs) are interesting new diagnostic targets that may provide important insights into the molecular pathogenesis of breast cancer. Here we evaluated, for the first time, the feasibility and clinical utility of circulating miRs as biomarkers for the detection and staging of breast cancer.


METHODS
The relative concentrations of breast cancer-associated miR10b, miR34a, miR141 and miR155 were measured in the blood serum of 89 patients with primary breast cancer (M0, n = 59) and metastatic disease (M1, n = 30), and 29 healthy women by a TaqMan MicroRNA Assay.


RESULTS
The relative concentrations of total RNA (P = 0.0001) and miR155 (P = 0.0001) in serum significantly discriminated M0-patients from healthy women, whereas miR10b (P = 0.005), miR34a (P = 0.001) and miR155 (P = 0.008) discriminated M1-patients from healthy controls. In breast cancer patients, the changes in the levels of total RNA (P = 0.0001), miR10b (P = 0.01), miR34a (P = 0.003) and miR155 (P = 0.002) correlated with the presence of overt metastases. Within the M0-cohort, patients at advanced tumor stages (pT3 to 4) had significantly more total RNA (P = 0.0001) and miR34a (P = 0.01) in their blood than patients at early tumor stages (pT1 to 2).


CONCLUSIONS
This pilot study provides first evidence that tumor-associated circulating miRs are elevated in the blood of breast cancer patients and associated with tumor progression.
Institute of Tumor Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. c.roth@uke.uni-hamburg.de
Carina
C
Roth
Brigitte
B
Rack
Volkmar
V
Müller
Wolfgang
W
Janni
Klaus
K
Pantel
Heidi
H
Schwarzenbach
D014408:Biomarkers, Tumor / Q000097:blood*; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D015870:Gene Expression; D006801:Humans; D035683:MicroRNAs / Q000097:blood*; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D010865:Pilot Projects; D016133:Polymerase Chain Reaction
D014408:Biomarkers, Tumor; D035683:MicroRNAs