INTRODUCTION: The most recent United Kingdom (NICE, 2009) guidelines recommend neoadjuvant chemotherapy as the most appropriate initial treatment for locally advanced breast cancer followed by mastectomy. Neoadjuvant chemotherapy should also be offered to patients with early breast cancer who are considering breast conserving surgery that is not advisable at presentation. However, the evidence base is still gathering. This study reviews the recent experience of neoadjuvant chemotherapy in a large United Kingdom breast unit according to breast cancer subtype. METHODS: Retrospective chart review of patients who received neoadjuvant chemotherapy for breast cancer at University Hospitals of Leicester between January 2008 and March 2011. Patients were identified from the unit database. Breast cancers were typed according to immunehistochemical marker profile: luminal A (ER or PR positive, HER2 negative), luminal B (ER or PR positive, HER2 positive), triple negative (ER and PR negative, HER2 negative), and HER2 positive (ER and PR negative, HER2 positive). RESULTS: Of 2,489 new patients with breast cancer seen during the study period, 153 patients received neoadjuvant chemotherapy. 20 patients had lobular-type cancers, and the remaining 133 patients had ductal- or mixed-type histology. 101 patients had locally advanced disease and 52 patients presented as early breast cancer. 24 of all patients (15 %) achieved complete pathological response. 18 patients (12 %) never proceeded to surgery, eight of whom died during the study period. In total to date, 23 patients (15 %) have died including one death due to complications from chemotherapy. Of 120 patients initially scheduled for mastectomy, the tumor was downsized in 26 patients (22 %) so that they were able to undergo breast conserving surgery (BCS), with margins involved in six patients. The outcome of neoadjuvant chemotherapy according to breast cancer subtype is presented (Tables 1 and 2). CONCLUSIONS: In our experience, patients receive neoadjuvant chemotherapy for breast cancer for a variety of indications. Compared to our standard population of breast cancer patients, early mortality remains relatively high, particlularly in the hormone receptor negative subtypes. BCS conversion rates were similar across breast cancer subtypes, but BCS was less likely to be successful in the Luminal A group. Luminal A cancers were also significantly less likely to achieve pCR after neoadjuvant chemotherapy. Breast cancer subtype should be taken into account when scheduling patients for neoadjuvant chemotherapy. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-14-15.