Background: Adjuvant trastuzumab has been routinely used in HER2-positive operable breast cancer patients. Prognostic factors remain to be well characterized in these patients and might correlate with primary and/or acquired resistance to trastuzumab.
Patients And Methods: The study subjects were 78 HER2-positive operable breast cancer patients treated with adjuvant chemotherapy followed by 1-year trastuzumab between 2005 and 2010 in our institute.