A Study of Pertuzumab in Addition to Chemotherapy and Trastuzumab as Adjuvant Therapy in Participants With Human Epidermal Growth Receptor 2 (HER2)-Positive Primary Breast Cancer

Inclusion Criteria:

• Non-metastatic operable primary invasive HER2-positive carcinoma of the breast thatis histologically confirmed, and adequately excised

• Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to (</=) 1

• Known hormone receptor status (estrogen receptor and progesterone receptor)

• The interval between definitive surgery for breast cancer and the first dose ofchemotherapy must be no more than 8 weeks (56 days). The first cycle of chemotherapymust be administered within 7 days of randomization or on Day 56, whichever occursfirst

• Baseline left ventricular ejection fraction (LVEF) greater than or equal to (>/=) 55percent (%) measured by echocardiogram (ECHO) or Multiple-Gated Acquisition (MUGA)Scan

• Confirmed HER2 positive status

• Completion of all necessary baseline laboratory and radiologic investigations priorto randomization

• Women of childbearing potential and male participants with partners of childbearingpotential must agree to use effective contraception (as defined by the protocol) bythe participant and/or partner for the duration of the study treatment and for atleast 7 months after the last dose of study drug

Exclusion Criteria:

• History of any prior (ipsi- and/or contralateral) invasive breast cancer

• History of non-breast malignancies within the 5 years prior to study entry, exceptfor carcinoma in situ of the cervix, carcinoma in situ of the colon, melanoma insitu, and basal cell and squamous cell carcinomas of the skin

• Any "clinical" T4 tumor as defined by primary tumor/regional lymph nodes/distantmetastasis (TNM), including inflammatory breast cancer

• Any node-negative tumor

• Any previous systemic chemotherapy for cancer or radiotherapy for cancer

• Prior use of anti-HER2 therapy for any reason or other prior biologic orimmunotherapy for cancer

• Concurrent anti-cancer treatment in another investigational trial

• Serious cardiac or cardiovascular disease or condition

• Other concurrent serious diseases that may interfere with planned treatmentincluding severe pulmonary conditions/illness

• Abnormal laboratory tests immediately prior to randomization

• Pregnant or lactating women

• Sensitivity to any of the study medications or any of the ingredients or excipientsof these medications