Patient description: The patient is a 42 year-old postmenopausal woman who had a screening sonogram which revealed an abnormality in the right breast. She had no palpable masses on breast exam. Core biopsy was done and revealed a 1.8 cm infiltrating ductal breast carcinoma in the left upper outer quadrant. Lumpectomy was done and the surgical margins were clear. The tumor was HER2-positive and ER/PR negative. Axillary sampling revealed 1 positive lymph node out of 12 sampled. CXR was unremarkable. She is using “well women” multivitamins daily and no other medication. She smokes frequently and consumes alcohol occasionally. She is in a relation with only one partner and has a history of 3 pregnancies and live births. She breastfed all three children.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Breast Ductal Carcinoma In Situ The patient must have consented to participate and must have signed and dated an appropriate Institutional Review Board (IRB)-approved consent form that conforms to federal and institutional guidelines for the study treatment and for the pre-entry tumor block submission for HER2 testing and B-43 correlative studies Patients must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 (0 = fully active, able to carry on all pre-disease performance without restriction; 1 = restricted in physically strenuous activity but ambulatory) On histologic examination, the tumor must be ductal carcinoma in situ (DCIS) (patients with mixed DCIS and lobular carcinoma in situ [LCIS] are eligible) The DCIS must be HER2-positive as determined by central testing Estrogen and/or progesterone receptor status must be determined prior to randomization (patients with DCIS that is hormone receptor positive or negative are eligible) All DCIS must have been resected by lumpectomy The margins of the resected specimen must be histologically free of DCIS; for patients in whom pathologic examination demonstrates DCIS present at the line of resection, re-excision(s) may be performed to obtain clear margins (patients who require mastectomy are not eligible) If axillary staging is performed, nodal staging must be pN0, pN0(i-), pN0(i+) which is defined as isolated tumor cells =< 0.2 mm, regardless of the method of detection, i.e., immunohistochemistry (IHC) or hematoxylin & eosin (H&E), pN0(mol-), or pN0(mol+); note: axillary staging is not required The interval between the last surgery for excision of DCIS (lumpectomy or re-excision of lumpectomy margins) and randomization must be no more than 120 days  Invasive (including microinvasion staged as T1mic) breast cancer (patients with DCIS "suspicious" for microinvasion, but not confirmed, are eligible) Nodal staging of pN1 (including pN1mi) (note: axillary staging is not required) DCIS present in more than one quadrant (multicentric) Masses or clusters of calcification that are clinically or mammographically suspicious unless biopsied and proven to be benign (if DCIS is found, the patient is eligible if the DCIS was in the same quadrant of the ipsilateral breast and was resected with clear margins) Contralateral breast cancer (including DCIS) Whole breast irradiation administered before randomization (partial breast irradiation is prohibited) Prior history of breast cancer, including DCIS (patients with a history of LCIS are eligible) Prior anthracycline chemotherapy for any malignancy Cardiac disease that would preclude the use of the drugs included in the B-43 treatment regimens; this includes but is not confined to Active cardiac disease