CYP19A1 and breast cancer: Treatmentincludes surgery, radiation therapy, and systemic therapy, which ishighly dependent on the subtype of breast cancer.2,3 Themost common subtype is hormone-positive (positive for estrogen orprogesterone receptor) breast cancer, which is usually treated withendocrine therapies such as aromatase inhibitors or estrogen receptorantagonist tamoxifen.