ERBB2 and breast carcinoma: 9 In addition, some authors offer adjuvant chemotherapy for ER-positive, HER2-negative breast cancer for tumor size greater than 1 cm or if there is nodal involvement.10 The choice of chemotherapeutic regimen offered is tailored to the individual case. While national practice guidelines exist, the choice of a specific regimen is made by the treating oncologist (Table 3).10,11