Background: Amplification of the Her2neu oncogene is a well known indicator of poor prognosis in breast cancer patients. The implementation into the clinical setting of therapeutical strategies directly targeting the Her2neu gene product, has create the need for the development of non-invasive analytical techniques in order to monitoring minimal residual disease and response to the treatment.
Methods: To detect the expression of Her2neu mRNA in peripheral blood, we developed a specific real-time quantitative reverse transcription-PCR (QPCR) assay. The analyses were performed on blood samples obtained from 30 breast cancer patients positive for Her2neu overexpression by immunohistochemical analysis (IHC), 10 breast cancer patients negative for Her2neu overexpression, and 24 healthy controls.
Results: Her2neu positive tumors showed a significant increase in mRNA transcripts as compared with both healthy controls (n=24) and Her2neu negative patients (n=10). After establishing a cut-off value, 18 out of the 30 Her2neu positive patient scored positive for Her2neu expression, whereas only 1 out of the 10 Her2neu negative patients was weakly positive.
Conclusions: Her2neu QPCR is suitable method for Her2neu overexpression detection in peripheral blood from clinical samples of breast cancer patients. QPCR could be used to identify breast cancer patients with poor prognosis and for monitoring response to the therapy.