ERBB2 and breast cancer: However, there are conflicting results regarding the frequency of detected human epidermal growth factor receptor 2 (HER2)-positive BC among SDBC, since most series have not found differences when compared with NSDBC [7,10,11,12,13,14,15], while other studies have reported a lower prevalence of HER2-positive tumors within SDBC group [3,4,13,16].