ESR1 and neoplasm: Patients were screened using a backward regression, with age, baseline T–stage, baseline N–stage, histological grade, CNB ER, PR, HER–2, Ki67, AR, AR/ER, AR/PR levels, residual tumor TN stage, residual tumor ER, PR, HER, Ki67, and ΔKi67 as the factors initially included (Table 6).