Four significant adjuvant trials have investigated different approaches with trastuzumab as follows: Herceptin® Adjuvant (HERA),188 North Central Cancer Treatment Group (NCCTG) N9831, NSABP B-3132,86,87, and Breast Cancer International Research Group (BCIRG) 006186 consisting of more than 13,000 female cases with HER2-positive EBC. This evidence concerns the gene ERBB2 and cancer.