NCCN Guidelines Insights Breast Cancer, Version 1.2016.

These NCCN Guideline Insights highlight the important updates to the systemic therapy recommendations in the 2016 NCCN Guidelines for Breast Cancer. In the most recent version of these guidelines, the NCCN Breast Cancer Panel included a new section on the principles of preoperative systemic therapy. In addition, based on new evidence, the panel updated systemic therapy recommendations for women with hormone receptor-positive breast cancer in the adjuvant and metastatic disease settings and for patients with HER2-positive metastatic breast cancer. This report summarizes these recent updates and discusses the rationale behind them.