Clinical Utility of Multigene Profiling Assays in Invasive Early-Stage Breast Cancer

This is a clinical practice guideline for women diagnosed with invasive early-stage breast cancer. The guideline discusses the use of different multigene profiling assays for determining risk profiles (high-risk vs low-risk) in patients with estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative tumours. The validity and clinical utility of different assays are examined, including Oncotype DX, Prosigna, MammaPrint, EndoPredict, and EPclin. In addition, assays are specifically compared to Oncotype DX, the only assay that was publicly funded and part of standard practice in Ontario at the time of publication.