Possible Prognostic Role of HER2/Neu in Ductal Carcinoma In Situ and Atypical Ductal Proliferative Lesions of the Breast.

HER2/neu is a well-established prognostic and predictive factor for invasive breast cancer. However, the role of HER2/neu in ductal breast carcinoma in situ (DCIS) is debated and recent data have suggested that it is mainly linked to in situ local recurrence. Although molecular data suggest that atypical ductal hyperplasia (ADH) and duct carcinoma in situ (DCIS) are related lesions, albeit with vastly different clinical implications, the role of HER2/neu expression in atypical ductal hyperplasia is not well defined either.