Adverse events

Participants received neoadjuvant treatment with dose-dense doxorubicin and cyclophosphamide (ddAC), with administration of doxorubicin 60 milligrams per square meter (mg/m\^2) intravenously (IV) once every 2 weeks (q2w) and cyclophosphamide 600mg/m\^2 IV q2w for 4 cycles, followed by paclitaxel 80mg/m\^2 IV once weekly (qw) for 12 weeks. Pertuzumab (840 milligrams \[mg\] IV loading dose then 420mg IV q3w) and trastuzumab (8 milligrams per kilogram \[mg/kg\] IV loading dose then 4mg/kg IV q3w) were administered along with paclitaxel for 4 cycles (8 cycles of chemotherapy in total prior to surgery). Following surgery, participants received adjuvant treatment with pertuzumab and trastuzumab IV q3w (up to 13 cycles), for a total of 17 cycles of pertuzumab and trastuzumab therapy during the study. Radiotherapy and adjuvant hormonal therapy were also given as clinically indicated. Following treatment completion/discontinuation, participants were followed for safety and efficacy for up to 5 years.

Participants received neoadjuvant treatment with 5-fluorouracil, epirubicin, and cyclophosphamide (FEC), with administration of 5-fluorouracil 500mg/m\^2 intravenously (IV) q3w, epirubicin 100mg/m\^2 IV q3w, and cyclophosphamide 600mg/m\^2 IV q3w for 4 cycles, followed by docetaxel (with starting dose of 75mg/m\^2 in Cycle 5, then 100mg/m\^2 for Cycles 6-8) q3w for 4 cycles. Pertuzumab (840 mg IV loading dose then 420mg IV q3w) and trastuzumab (8 mg/kg IV loading dose then 4mg/kg IV q3w) were given along with doectaxel for 4 cycles (8 cycles of chemotherapy in total prior to surgery). Following surgery, participants received adjuvant treatment with pertuzumab and trastuzumab IV q3w (up to 13 cycles), for a total of 17 cycles of pertuzumab and trastuzumab therapy during the study. Radiotherapy and adjuvant hormonal therapy were also given as clinically indicated. Following treatment completion/discontinuation, participants were followed for safety and efficacy for up to 5 years.