Patient description: The patient is a 45-year-old postmenopausal woman with cytologically confirmed breast cancer. A core biopsy revealed a 3 cm invasive ductal breast carcinoma in the left upper outer quadrant. The tumor is HER2-positive and ER/PR negative. Axillary sampling revealed 5 positive lymph nodes. CXR was remarkable for metastatic lesions. The patient is using multivitamins and iron supplements. She does not smoke or consume alcohol. She is not sexually active and has no children. She is a candidate for tumor resection and agrees to do so prior to chemotherapy.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  HER2 Positive Breast Carcinoma Hormone Receptor Positive Breast Adenocarcinoma Stage IB Breast Cancer AJCC v7 Stage IIA Breast Cancer AJCC v6 and v7 Stage IIB Breast Cancer AJCC v6 and v7 Stage IIIA Breast Cancer AJCC v7 Stage IIIB Breast Cancer AJCC v7 Stage IIIC Breast Cancer AJCC v7 Patients should have a life expectancy of at least 10 years, excluding their diagnosis of breast cancer; (comorbid conditions should be taken into consideration, but not the diagnosis of breast cancer) Women of reproductive potential must agree to use an effective non-hormonal method of contraception during study therapy (chemotherapy, trastuzumab, pertuzumab, and estrogen deprivation therapy) and for at least 7 months after the last dose of study therapy Submission of tumor samples is required for all patients; the local pathology department policy regarding release of tumor samples must be considered in the screening process; patients whose tumor samples are located in a pathology department that by policy will not submit any samples for research purposes should not be approached for participation in the B-52 trial The patient must have signed and dated an Institutional Review Board (IRB)-approved consent form that conforms to federal and institutional guidelines The patient must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 Clinical staging for the primary tumor can be cT1c (must be 2.0 cm) or T2-T4 if clinically node negative; if the regional lymph nodes are cN1 and cytologically or histologically positive or if cN2-N3 with or without a biopsy, the primary breast tumor can be cT0-T4 The diagnosis of invasive adenocarcinoma of the breast must have been made by core needle biopsy Ipsilateral axillary lymph nodes must be evaluated by imaging (mammogram, ultrasound, and/or magnetic resonance imaging [MRI]) within 6 weeks prior to randomization; if suspicious or abnormal, fine needle aspirate (FNA) or core biopsy is recommended, also within 6 weeks prior to randomization; findings of these evaluations will be used to determine the nodal status prior to randomization Nodal status negative  FNA alone to diagnose the breast cancer Excisional biopsy or lumpectomy performed prior to randomization Surgical axillary staging procedure prior to randomization; pre-neoadjuvant therapy sentinel node biopsy is not permitted Definitive clinical or radiologic evidence of metastatic disease; (chest imaging [mandatory for all patients] and other imaging [if required] must have been performed within 90 days prior to randomization) Synchronous bilateral invasive breast cancer Synchronous or previous contralateral invasive breast cancer; (patients with synchronous and/or previous contralateral ductal carcinoma in situ [DCIS] or lobular carcinoma in situ [LCIS] are eligible) Any previous history of ipsilateral invasive breast cancer or ipsilateral DCIS; (patients with synchronous or previous ipsilateral LCIS are eligible) Treatment including radiation therapy (RT), chemotherapy, targeted therapy, or endocrine therapy for the currently diagnosed breast cancer prior to randomization Previous endocrine therapy such as raloxifene or tamoxifen (or other selective estrogen receptor modulator [SERM]) or an aromatase inhibitor for any malignancy Previous therapy with anthracycline, taxanes, carboplatin, trastuzumab, or other HER2 targeted therapies for any malignancy