ESR1 and breast carcinoma: Comparison of the prognostic value of six multigene signatures, including Clinical Treatment Score, four immunohistochemical markers (IHC4), RS, ROR, Breast Cancer Index (BCI), and EPclin in 774 postmenopausal women with ER-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer also demonstrated that ROR, BCI, and EPclin are more prognostic for overall and late distant recurrence than RS in patients with lymph node-negative breast cancer (15).