Genomic Health, Inc. announced that its Oncotype DX Breast Recurrence Score test and the TAILORx results have been recommended to guide chemotherapy treatment use in patients with node-negative early-stage breast cancer by the American Society of Clinical Oncology (ASCO) in its 2019 Guidelines for Use of Biomarkers to Guide Decisions on Adjuvant Systemic Therapy. Using the strong and high level of evidence from TAILORx, the updated ASCO guidelines increase the proportion of women who can be effectively treated without chemotherapy based on the Oncotype DX results, highlighting the importance of testing all medically eligible patients as standard of care. TAILORx, sponsored by the National Cancer Institute (NCI) and conducted by the ECOG-ACRIN Cancer Research Group, involved 10,273 women across 1,100 trial sites in six participating countries. The study results, which were presented during the Plenary Session at the 2018 ASCO Annual Meeting last June and simultaneously published in The New England Journal of Medicine, demonstrated that the Oncotype DX Breast Recurrence Score test definitively identifies the vast majority of women with early-stage breast cancer who receive no benefit from chemotherapy, and the important minority of women for whom chemotherapy benefit can be life-saving. Patients with an Oncotype DX Breast Recurrence Score result of 25 or less up to about 80% of patients may be safely spared chemotherapy and its well-known side effects, while those with scores of 26 to 100 may receive a life-saving benefit from chemotherapy.