ERBB2 and breast cancer: After adjusting the analysis by the confounders (age, year of BC diagnosis, Charlson comorbidity index, income quintile, urban/rural residence status, ER, HER2 and LN status, histological grade, type of surgery and radiation treatment), the 5-year OS was 93.8% for those treated with TC, 92.7% for those treated with ACT and 90.7% for those treated with FEC-D, (p = 0.052).