With the help of the large‐scale clinical data and expression level information from TCGA, we found that the high ESR1 methylation group had a strong correlation with bigger tumor size, distant metastasized status, advanced clinical stage, negative ERα and/or PR, positive HER2 status, and higher invasive ductal carcinoma percentage in BC patients. This evidence concerns the gene ESR1 and invasive ductal breast carcinoma.