Highlights of the San Antonio Breast Cancer Symposium 2015: Part 2

38th San Antonio Breast Cancer Symposium (SABCS), San Antonio, TX, USA, 8–12 December 2015 The 38th annual San Antonio Breast Cancer Symposium was convened in San Antonio (TX, USA) on 8–12 December 2015. More than 7000 clinicians and scientists from around the world participated in the symposium, which featured a range of presentations and keynote talks pertaining to breast cancer screening, prevention, loco-regional and systemic therapies. This two-part report highlights a selection of important studies presented at this premier breast cancer event with part 1 focusing on radiotherapy treatment, translational approaches to immunotherapy and longer term cardiotoxicity from anti-HER2 therapies. The second part of this report will discuss a range of topics including de-escalation of chemotherapy regimens in luminal A tumors, the prognostic relevance of circulating tumor cells, the optimum treatment of triple-negative breast cancer and shifting attitudes to primary surgical treatment.