NR4A1 and breast cancer: <h4>Purpose</h4>To evaluate the clinical benefit of extended endocrine therapy (eET) after 5 years of adjuvant treatment with luteinizing hormone-releasing hormone agonists (LHRHa) in premenopausal women with node-positive, hormone receptor-positive early breast cancer (eBC).<h4>Methods</h4>We conducted a cohort study analysis on two prospectively collected data sets (the Young Women's Breast Cancer Study and IEO Breast Cancer Cohort).