A large clinical trial has found that postmenopausal women with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer that has spread to as many as three lymph nodes and who have a 21-gene recurrence score (RS) of 25 or lower can safely skip having chemotherapy and only take endocrine therapy after breast cancer surgery. The results are published in the New England Journal of Medicine.