ESR1 and breast cancer: Grade (HR = 2.169, p = 0.002), ER (HR = 0.4, p < 0.001), PR (HR 0.494, p = 0.005), tumor size (HR = 4.362, p < 0.001), lymph node (HR = 2.689, p < 0.001), LVI (HR = 2.960, p < 0.001), dermal invasion (HR = 3.060, p = 0.003), perineural invasion (HR = 2.558, p < 0.001), surgical method (HR = 2.981, p < 0.001 ), and hormone therapy (HR = 2.666, p < 0.001) were significantly associated with breast cancer progression, including mortality and disease progression.