ERBB2 and invasive ductal breast carcinoma: We report here real-world clinical outcomes of patients receiving a shortened 12-week neoadjuvant regimen of weekly paclitaxel and carboplatin administered with trastuzumab and pertuzumab (12wTCHP).<h4>Methods</h4>We conducted a retrospective analysis of patients with HER2-positive breast cancer treated with neoadjuvant 12wTCHP in a single tertiary medical center.<h4>Results</h4>Of forty-four eligible patients receiving 12wTCHP, 41 had invasive ductal carcinoma (IDC, 93%), and 64% were ER-positive.