Sparano JA, et al. - Through a prospective trial with 9,427 women, researchers sought to determine if the risk of recurrence in patients with breast cancer combined with a score based on a 21-gene assay can add prognostic information. An assay of 21 genes had been performed in women with hormone-receptor–positive, human epidermal growth factor receptor 2–negative, axillary node–negative breast cancer, and then the clinical risk of recurrence was categorized as low or high based on tumor size and histologic grade. Premenopausal women who could benefit from more effective therapy could be identified with clinical-risk stratification, when added to the 21-gene recurrence score.