The results of this study demonstrated that routine use of the Oncotype DX® test in women with HR+, HER2−, N0 or N1, early BC at high clinicopathological risk of distant recurrence would be associated with a substantial reduction in CT use, improved QoL, and lower costs when compared to SoC comprising clinicopathological risk appraisal only. Here, ERBB2 is linked to breast cancer.