The natural history of HER2-positive early breast was dramatically changed in 2005 by the results of 4 randomised phase III trials evaluating the combination of chemotherapy with adjuvant trastuzumab, the first drug in the anti-HER2 class. HERA, BCIRG-006, NCCTG 9831 and NSABP-B31 established 1 year of adjuvant trastuzumab as the...