A Randomized Multicenter, Double-blind, Placebo-controlled Comparison of Chemotherapy Plus Trastuzumab Plus Placebo Versus Chemotherapy Plus Trastuzumab Plus Pertuzumab as Adjuvant Therapy in Patients With Operable HER2-positive Primary Breast Cancer

Inclusion Criteria:

- Adult patients. >/= 18 years of age

- Non-metastatic primary invasive HER2-positive carcinoma of the breast that is
adequately excised and that is node-positive (except T0)

- Eastern Cooperative Oncology Group (ECOG) performance status
- The interval between definitive surgery for breast cancer and the first dose of
chemotherapy must be no more than 8 weeks (56 days). The first cycle of chemotherapy
must be administered within 7 days of randomization or on Day 56, whichever occurs
first.

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

- Baseline LVEF >/= 55%

- Women of childbearing potential and male participants with partners of childbearing
potential must agree to use effective contraception (as defined by the protocol) by
the patient and/or partner for the duration of the study treatment and for at least 6
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, except
for carcinoma in situ of the cervix, carcinoma in situ of the colon, melanoma in
situ, and basal cell and squamous cell carcinomas of the skin

- Any "clinical" T4 tumor as defined by TNM, including inflammatory breast cancer

- Any previous systemic chemotherapy for cancer or radiotherapy for cancer

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

- Concurrent anti-cancer treatment in another investigational trial

- Serious cardiac or cardiovascular disease or condition

- Pregnant or lactating women