Patients will be recruited from the medical and surgical oncology and/or the hematology/oncology clinics at the individual study sites. All patients will be properly consented. 4.1.1 Subject Selection Potentially eligible patients, specifically NP (or NN if negative for both ER and PR) breast cancer patients with HER2 1+ or 2+ expressing tumors will be identified by staff in the medical and surgical and/or the hematology/oncology clinics at the individual study sites. IHC testing of primary tumor is necessary for trial inclusion. To be eligible for enrollment, patients must have HER2 1+ or 2+ tumors. For those with HER2 2+ tumors, FISH or Dual-ISH testing must also be performed. FISH or Dual-ISH results must be non-amplified (or ≤2.0). HER2 2+ patients with FISH or Dual-ISH amplification (>2.0) will not be eligible for this trial. Patients who undergo neoadjuvant treatment regimens will be permitted in this trial.