Detection of human mammaglobin A mRNA in peripheral blood of breast cancer patients before treatment and association with metastasis

Background: Mammaglobin A (MGA), mainly expressed in the breast epithelium, is over expressed in breast cancer, and has been established as a tumor and promissory marker for the early detection of metastasis. Aim: The main aim of this study was to evaluate the association between the presence of the MGA transcript in the peripheral blood of Brazilian breast cancer patients and healthy women and the development of breast cancer and tumor progression. Material and methods: The expression of the MGA transcript in peripheral blood of 102 breast cancer patients and 102 healthy women was assessed by RT-PCR. Results: MGA mRNA was expressed in the peripheral blood of 39 breast cancer patients and in none of the women from the control group. The presence of MGA was significantly associated with presence of metastasis and age at onset after 60 years. The presence of MGA mRNA in peripheral blood displayed a sensitivity of 38.2%, specificity of 100.0%, positive predictive value (PPV) of 100.0%, and negative predictive value (NPV) of 61.8% as a breast cancer marker. Conclusion: This study provides additional evidence of the presence of MGA in the peripheral blood of breast cancer patients, and its applicability as an efficient biomarker for breast cancer (High specificity and PPV). To our knowledge, this is the first study to assess the expression of MGA mRNA in peripheral blood obtained from the Brazilian population