Study in Participants With Early-Stage or Locally Advanced Human Epidermal Growth Factor Receptor (HER) 2-Positive Breast Cancer to Evaluate Treatment With Trastuzumab Plus (+) Pertuzumab + Docetaxel Compared With Trastuzumab + Placebo + Docetaxel

Fluorouracil 500-600 milligrams per square meter (mg/m2), epirubicin 90-120 mg/m2, and cyclophosphamide 500-600 mg/m2 by intravenous (IV) infusion every 3 weeks for three cycles (Cycles 5-7). FEC chemotherapeutic agents will be administered following surgery on Day 1 of each specified cycle.

All participants who are eligible for surgery will undergo surgery and have their pathologic response evaluated.

Docetaxel IV infusion in 3-week cycles. Neoadjuvant treatment: 75 mg/m2 for Cycles 1-4.

Pertuzumab IV infusion in 3-week cycles. Prior to surgery (neoadjuvant treatment): 840 milligrams (mg) loading dose for Cycle 1, followed by 420 mg for Cycles 2-4. After surgery and 3 cycles of FEC chemotherapy (adjuvant treatment): 840 mg loading dose for Cycle 8, followed by 420 mg for Cycles 9-20)

Placebo by IV infusion in 3-week cycles as neoadjuvant treatment (Cycles 1-4)and as adjuvant treatment (Cycles 8-20)

Trastuzumab IV infusion in 3-week cycles. Neoadjuvant treatment: 8 milligrams per kilogram (mg/kg) loading dose for Cycle 1, followed by 6 mg/kg for Cycles 2-4. Adjuvant treatment: 8 mg/kg loading dose for Cycle 8, followed by 6 mg/kg for Cycles 9-20.