ESR1 and neoplasm: The results of the Cox models—adjusted on the year of diagnosis, age, T category, tumor grade, immunohistochemistry (ER, PR, HER2), breast-conserving surgery, radiotherapy, adjuvant systemic treatment, time between diagnosis and treatment, and number of positive lymph nodes—showed that ALND was associated with a worse survival outcome (HR 1.96; 95%CI 1.91–2.00, p < 0.001), and the number of removed lymph nodes was proportional to higher specific mortality (HR 1.0033; 95%CI 1.0022–1.0045, p < 0.001).