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,  Malignant Neoplasm of Breast Breast Cancer Must have histologically or cytologically confirmed triple negative (ER-/PR-/HER2-) invasive breast cancer, clinical stage I-III at diagnosis (AJCC 6th edition) based on initial evaluation by physical examination and/or breast imaging prior to study registration. NOTE: ER, PR and HER2 status will be confirmed by central pathology review prior to randomization. ER and PR will be considered negative if ≤ 1% of cells stain weakly positive. HER2 will be considered negative if scored 0 or 1+ by immunohistochemistry (IHC) or 2+ by IHC associated with a fluorescence in situ hybridization (FISH) ratio of < 2.0 or < 6 copies per cell Must have completed preoperative (neoadjuvant) chemotherapy. NOTE: Acceptable preoperative regimens an anthracycline or a taxane, or both. Participants who received preoperative therapy as part of a clinical trial may enroll. Participants may not have received adjuvant chemotherapy after surgery prior to randomization. Bisphosphonate use is allowed Must have completed definitive resection of primary tumor. The most recent surgery for breast cancer must have been completed at least 14 days prior (but no more than 84 days prior) to study registration. NOTE: Negative margins for both invasive and ductal carcinoma in situ (DCIS) are desirable, however participants with positive margins may enroll if the treatment team believes no further surgery is possible and patient has received radiotherapy. Participants with margins positive for lobular carcinoma in situ (LCIS) are eligible. Either mastectomy or breast conserving surgery (including lumpectomy or partial mastectomy) is acceptable Must have significant residual invasive disease at the time of definitive surgery following preoperative chemotherapy. Significant residual disease is defined as at least one of the following Residual Cancer Burden (RBC) classification II or III6 Residual invasive disease in the breast measuring at least 2 cm. The presence of DCIS without invasion does not qualify as residual disease in the breast Residual invasive disease in the breast measuring at least 1cm with any lymph node involvement (does not metastases in lymph node which are only detected by immunohistochemistry) Any lymph node involvement that results in 20% cellularity or greater regardless of primary tumor site involvement (includes no residual disease in the breast) Must have an FFPE tumor block with tumor cellularity of 20% or greater. NOTE: Prior to randomization, the tumor cellularity will be confirmed by central pathology review and percent values will be double checked at Paradigm (a Next Generation Sequencing Company) Whole breast radiotherapy is required for participants who underwent breast-conserving therapy, including lumpectomy or partial mastectomy. Participants must have completed radiotherapy at least 14 days prior (but no more than 84 days prior) to study registration  No stage IV (metastatic) disease, however no specific staging studies are required in the absence of symptoms or physical exam findings that would suggest distant disease No treatment with any investigational agent within 30 days prior to study registration No history of chronic hepatitis B or or untreated hepatitis C No clinically significant infections as judged by the treating physician No active second malignancy (except non-melanomatous skin cancer or incidental prostate cancer found on cystectomy): Active second malignancy is defined as a current need for cancer therapy or a high possibility (> 30%) of recurrence during the study. Previous contralateral breast cancer is allowable unless it meets "active" as stated above