Background:Patients with early stage breast cancer with same treatment strategy can have markedly different outcomes. Human epidermal growth factor receptor 2 (HER2/nue) gene amplification or the subsequent overexpression of protein has been proved to be associated with patient's outcome and response to anthracyclins-based regimens.Objectives:This study assessed prognostic value of HER2/nue marker in patients with early stage breast cancer who received adjuvant chemotherapy with anthracyclins-based regimens.Materials and Methods:Fifty tissue samples from patients with primary breast cancer of moderate risk receiving sequential adjuvant chemotherapy with anthracyclins-based regimens were assessed to evaluate HER2/nue gene status (quantified by Immunohistochemistry and fluorescence in situ hybridization) retrospectively. Besides, correlation of HER2/neu with patients' characteristics and outcome was studied.Results:HER2/neu amplification was identified in 19 (38%) of 50 patients. No significant difference regarding HER2/neu status was seen in clinic pathological characteristics of patients. Although Progression Free Survival (PFS) was shorter in HER2 overexpressed group, but uni/multivariate analysis adjusted for HER2 overexpression, nodal involvement, hormone receptor status, age and tumor size revealed no significant predictive and/or prognostic value for HER2 regarding PFS.Conclusions:This study on a limited number of patients treated with adjutant anthracyclins-based regimens, revealed that HER2/neu is not a unique strong predictor for outcome, thus according to combination of HER2/neu status and other clinical factors, it is necessary to distinguish patients at high risk of recurrence.