ESR1 and breast cancer: The risks for breast cancer death at 10 years for ER-positive patients treated with tamoxifen were 2.8% (95% CI 1.7–3.9%), 10.7% (95% CI 6.3–14.9%), and 15.5% (95% CI 7.6–22.8%) for patients with Recurrence Score values in the low, intermediate, and high risk categories, respectively (Table 5).