ESR1 and breast carcinoma: The comprehensive pathological assessment of breast cancer should be performed in alignment with the World Health Organization (WHO) classification [3] and the eighth edition of the American Joint Committee on Cancer (AJCC) Tumour, Node, Metastasis (TNM) staging system [4], and includes not only anatomical considerations but also crucial prognostic insights tied to tumor biology, such as tumor grade, estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), and available gene expression data [5].