HER2 positive breast cancer confers an aggressive clinical phenotype including accelerated cell growth, high risk of systemic metastasis and recurrence [3].To improve treatment outcome of this aggressive breast cancer, patients are treated with doxorubicin-based chemotherapy followed by adjuvant trastuzumab which is monoclonal antibody directed against HER2 receptors [4]. This evidence concerns the gene ERBB2 and breast carcinoma.