ERBB2 and breast cancer: As two patients had a synchronous bilateral BC, the subgroup activity analysis was performed on 42 tumors treated with EC → D ± T and 44 tumors treated with EC → Taxane ± T. In the as-treated analysis (42 tumors), in the HER2-positive population, treated with D in combination with T, pCR was observed in 6 out of 23 tumors (26%); 3 pCRs were reported out of 13 ER-positive tumors (23%) and 3 out of 10 ER-negative tumors (30%).