Inclusion Criteria:

- The tumor must be unilateral invasive adenocarcinoma of the breast on histologic
examination

- All of the following staging criteria (according to the 7th edition of the American
Joint Committee on Cancer [AJCC] Cancer Staging Manual) must be met:

- By pathologic evaluation, primary tumor must be pT1-3

- By pathologic evaluation, ipsilateral nodes must be pN0, pN1 (pN1mi, pN1a,
pN1b,pN1c), pN2a, pN2b, pN3a, or pN3b

- If pN0, one of the following criteria must be met:

- pT2 and estrogen receptor (ER) negative and progesterone receptor
(PgR) negative

- pT2 and ER positive (PgR status may be positive or negative) and
either grade 3histology or Oncotype DX Recurrence Score of >= 25; or

- pT3 regardless of hormone receptor status, histologic grade, and
Oncotype DX Recurrence Score

- No T4 tumors including inflammatory breast cancer

- No definitive clinical or radiologic evidence of metastatic disease

- NOTE: Chest imaging (mandatory for all patients) and other imaging (if required)
must have been performed within 90 days prior to randomization

- No synchronous or previous contralateral invasive breast cancer (patients with
synchronous and/or previous contralateral DCIS or lobular carcinoma in situ [LCIS]
are eligible)

- No previous ipsilateral invasive breast cancer or ipsilateral DCIS (patients with
synchronous or previous ipsilateral LCIS are eligible)

- HER2 status of the primary tumor must be evaluated prior to randomization; all
testing performed must indicate that the tumor is HER2-low as defined below

- IHC must be performed and the IHC staining results must indicate a score of 1+
(in situ hybridization [ISH] testing is not required) or 2+ (ISH must also be
performed and must indicate that the tumor is HER2-low as described below)

- If ISH testing is performed, test results must be as follows and IHC must be 1+
or 2+: The ratio of HER2 to CEP17 must be < 2.0 or, if a ratio was not
performed, the HER2 gene copy number must be < 4 per nucleus

- Note: If the IHC staining intensity is reported as a range, e.g., 0 to 1+ or 1+
to 2+, the higher intensity score in the range should be used to determine
eligibility

- No primary tumor with any of the following HER2 testing results:

- IHC staining intensity:

- 0 on all evaluations of specimens

- 3+ on evaluation of any specimen

- ISH with a ratio of HER2 to CEP17 >= 2.0 on evaluation of any specimen

- ISH result indicating HER2 gene copy number >= 4 per nucleus on evaluation of
any specimen

- The patient must have undergone either a total mastectomy or breast-conserving
surgery (lumpectomy) (patients who have had a nipple-sparing mastectomy are eligible)

- For patients who undergo lumpectomy, the margins of the resected specimen must
be histologically free of invasive tumor and DCIS as determined by the local
pathologist; if pathologic examination demonstrates tumor at the line of
resection, additional operative procedures may be performed to obtain clear
margins; if tumor is still present at the resected margin after re-excision(s),
the patient must undergo total mastectomy to be eligible (patients with margins
positive for LCIS are eligible without additional resection)

- For patients who undergo mastectomy, margins must be free of gross residual
tumor(patients with microscopic positive margins are eligible as long as
post-mastectomy RT of the chest wall will be administered)

- The interval between the last surgery for breast cancer (treatment or staging)
and randomization must be no more than 84 days

- The patient must have completed one of the procedures for evaluation of pathologic
nodal status listed below:

- Sentinel lymphadenectomy alone:

- If pathologic nodal staging based on sentinel lymphadenectomy is pN0 or
pN1b

- If pathologic nodal staging based on sentinel lymphadenectomy is pN1mi or
pN1a, the primary tumor must be T1 or T2 by pathologic evaluation and the
nodal involvement must be limited to 1 or 2 positive nodes

- Sentinel lymphadenectomy followed by removal of additional non-sentinel lymph
nodes if the sentinel node (SN) is positive

- Axillary lymphadenectomy with or without SN isolation procedures

- The patient must have ER analysis performed on the primary tumor prior to
randomization; if ER analysis is negative, then PgR analysis must also be performed
(either the core biopsy or surgical resection specimen can be used for ER/PgR
testing); patients with a primary tumor that is hormone receptor-positive or
receptor-negative are eligible

- Pre- or postmenopausal

- Eastern Cooperation Oncology Group (ECOG) performance status of 0 or 1

- Absolute neutrophil count (ANC) must be >= 1,200/mm^3

- Platelet count must be >= 100,000/mm^3

- Hemoglobin must be >= 10 g/dL

- Total bilirubin must be =< upper limit of normal (ULN) for the lab unless the patient
has a bilirubin elevation > ULN to 1.5 x ULN due to Gilbert disease or similar
syndrome involving slow conjugation of bilirubin

- Alkaline phosphatase must be =< 2.5 x ULN for the lab

- Aspartate aminotransferase (AST) must be =< 1.5 x ULN for the lab (if alanine
aminotransferase [ALT] is performed instead of AST [per institution's standard
practice], the ALT value must be =< 1.5 x ULN; if both were performed, the AST must
be =< 1.5 x ULN)

- Alkaline phosphatase and AST may not both be > the ULN

- Patients with AST or alkaline phosphatase > ULN are eligible for inclusion in the
study if liver imaging (CT, MRI, PET-CT, or PET scan) performed within 90 days prior
to randomization does not demonstrate metastatic disease and the above requirements
are met

- Patients with alkaline phosphatase that is > ULN but =< 2.5 x ULN or unexplained bone
pain are eligible for inclusion in the study if a bone scan, positron emission
tomography (PET)-computed tomography (CT) scan, or PET scan performed within 90 days
prior to randomization does not demonstrate metastatic disease

- The most recent post operative serum creatinine performed within 6 weeks prior to
randomization must be =< ULN for the lab

- Not pregnant or nursing

- Negative pregnancy test

- Left ventricular ejection fraction (LVEF) assessment must be performed within 90 days
prior to randomization; LVEF assessment performed by 2-dimensional (D) echo
cardiogram is preferred, however, multi-gated acquisition (MUGA) scan maybe
substituted based on institutional preferences

- For patients who will receive the TC chemotherapy regimen, the LVEF must be >=
50% regardless of the cardiac-imaging facility's lower limit of normal

- For patients who will receive the AC→WP chemotherapy regimen, the LVEF must be
>= 55% regardless of the cardiac-imaging facility's lower limit of normal

- NOTE: Since the pre-entry LVEF serves as the baseline for comparing subsequent
LVEF assessments, it is critical that this baseline study be an accurate
assessment. If the baseline LVEF is > 70%, the investigator is encouraged to
have the accuracy of the initial LVEF result confirmed and repeat the test if
the accuracy is uncertain

- No history of non-breast malignancies (except for in situ cancers treated only by
local excision and basal cell and squamous cell carcinomas of the skin) within 5
years prior to randomization

- No cardiac disease (history of and/or active disease) that would preclude the use of
the drugs included in the treatment regimens, including, but not limited to:

- Active cardiac disease:

- Angina pectoris that requires the current use of anti-anginal medication

- Ventricular arrhythmias except for benign premature ventricular
contractions

- Supraventricular and nodal arrhythmias requiring a pacemaker or not
controlled with medication

- Conduction abnormality requiring a pacemaker

- Valvular disease with documented compromise in cardiac function

- Symptomatic pericarditis

- History of cardiac disease:

- Myocardial infarction documented by elevated cardiac enzymes or persistent
regional wall abnormalities on assessment of left ventricle (LV) function

- History of documented congestive heart failure (CHF)

- Documented cardiomyopathy

- No hypertension defined according to the following ineligibility criteria:

- For patients who will receive TC (regardless of the patient's age): uncontrolled
hypertension defined as sustained systolic blood pressure (BP) > 150 mm Hg or
diastolic BP > 90 mm Hg (patients with initial BP elevations are eligible if
initiation or adjustment of BP medication lowers pressure to meet entry
criteria)

- For patients < 50 years old who will receive AC→WP: uncontrolled hypertension
defined as sustained systolic BP > 150 mm Hg or diastolic BP > 90 mm Hg
(patients with initial BP elevations are eligible if initiation or adjustment of
BP medication lowers pressure to meet entry criteria)

- For patients >= 50 years old who will receive AC→WP: uncontrolled hypertension
defined as sustained systolic BP > 150 mm Hg or diastolic BP > 90 mm Hg OR
controlled hypertension (systolic BP =< 150 mm Hg and diastolic BP =< 90 mmHg),
if anti-hypertensive medication(s) are needed

- NOTE: Patients who are not eligible based on the AC→WP regimen BP criteria but
who meet the TC regimen BP criteria are eligible for B-47 if the intended
chemotherapy regimen is changed to TC

- No active hepatitis B or hepatitis C with abnormal liver function tests

- No intrinsic lung disease resulting in dyspnea

- No poorly controlled diabetes mellitus

- No active infection or chronic infection requiring chronic suppressive antibiotics

- No nervous system disorder (paresthesia, peripheral motor neuropathy, or peripheral
sensory neuropathy) >= grade 2, per the Common Terminology Criteria for Adverse
Events (CTCAE) v4.0

- No conditions that would prohibit administration of corticosteroids

- No known hypersensitivity to any of the study drugs or excipients, e.g., polysorbate
80 and Cremophor EL

- No other non-malignant systemic disease that would preclude the patient from
receiving study treatment or would prevent required follow-up

- No psychiatric or addictive disorders or other conditions that, in the opinion of the
investigator, would preclude the patient from meeting the study requirements

- Concurrent participation in NSABP-B-39 allowed

- No previous therapy with anthracyclines, taxanes, or trastuzumab for any malignancy

- No chemotherapy or HER2-targeted therapy administered for the currently diagnosed
breast cancer prior to randomization

- No whole-breast radiation therapy (RT) prior to randomization or partial-breast RT
that cannot be completed on or before the date of randomization

- No use of any investigational product within 30 days prior to randomization

- No continued endocrine therapy such as raloxifene or tamoxifen (or other SERM) or an
aromatase inhibitor (patients are eligible if these medications are discontinued
prior to randomization)

- No continued use of sex hormonal therapy, e.g., birth control pills, ovarian hormone
replacement therapy (patients are eligible if these medications are discontinued
prior to randomization)

- No chronic daily treatment with corticosteroids with a dose of >= 10 mg/day
methylprednisol one equivalent (excluding inhaled steroids)

- No other concurrent chemotherapy

- No other concurrent targeted therapy for malignancy

- No partial-breast irradiation following randomization