An important feature of breast Paget’s disease is that in addition to the presence of tumor cells in the epidermis of the nipple-areola complex, approximately 80-90% of patients have other types of carcinoma, either intraductal or invasive, and not necessarily in the vicinity of the nipple-areola. Therefore, one of the keys to treating this disease is to manage the associated cancer in addition to the lesions of the nipple areola complex. For patients who have been diagnosed with Paget’s disease of the breast, the most important concern is often the following question: “With the eczema-like changes in the nipple and the diagnosis of Paget’s disease of the breast, is it early or advanced?” “Do I have to have surgery for my breast Paget’s disease? Can I have breast-conserving surgery? What kind of surgery is right for me?” “Do I need axillary lymph node dissection, do I need radiotherapy?” “Can Paget’s disease of the breast metastasize and spread? Will my other breast be more prone to develop?” To answer these questions, first of all, we should be clear about the staging of breast Paget’s disease (usually there are 3 cases): 1. simple breast Paget’s disease, no concomitant other cancers, no axillary lymph node and distant metastasis, then it is early stage cancer; breast Paget’s disease with ductal If Paget’s disease of the breast is accompanied by ductal carcinoma, without axillary lymph nodes and distant metastasis, then it is also an early stage carcinoma. If Paget’s disease of the breast is accompanied by invasive breast cancer, then it should be staged according to invasive cancer, and then it may not be early stage. Therefore, the appearance of eczema-like changes in the nipple areola does not indicate the early or late stage of the tumor, which may or may not be very early. The staging is mainly related to the associated carcinoma. Since Paget’s disease of the breast is a type of cancer, it has the potential to metastasize and spread. Early and reasonable treatment can improve the prognosis. Therefore, it should be treated actively. Treatment options for Paget’s disease of the breast should also be differentiated according to the above-mentioned conditions, with special attention to associated cancers. 2.Surgery. Surgery is a very important treatment modality for Paget’s disease of the breast and should be considered first unless there is an absolute contraindication to surgery. Without surgery, there is a high probability that survival will be adversely affected. The specific surgical procedure for breast Paget’s is also related to the presence of other breast cancers. The main surgical procedures include: mastectomy + sentinel lymph node biopsy on the affected side, modified radical mastectomy for breast cancer, and breast-conserving surgery for breast cancer. In case of simple breast Paget’s or no axillary lymph node metastasis in preoperative examination, total mastectomy + sentinel lymph node biopsy can be considered. In the case of Paget’s disease of the breast combined with intraductal carcinoma, the above surgical approach is also applicable. In case of Paget’s disease of the breast combined with invasive breast cancer, Paget’s disease can be left aside and treated as normal invasive breast cancer. The decision to biopsy the anterior sentinel lymph nodes and to perform axillary lymph node dissection is based on preoperative evaluation and postoperative pathology. For patients with metastasis on sentinel lymph node biopsy or preoperative evaluation of metastasis, modified radical mastectomy (total mastectomy + axillary lymph node dissection) is the surgical option. 3.Does breast Paget’s disease necessarily require mastectomy? In fact, patients with breast paget’s disease can also choose to undergo breast-conserving surgery: for simple breast paget’s disease (no lump is palpated and no abnormal changes are found on imaging), the nipple-areola complex and its deep glands can be removed, and the margins of the underlying breast tissue are guaranteed to be negative; if no suspicious metastasis is found on preoperative axillary lymph node examination If no suspicious metastasis is found in the preoperative axillary lymph node examination, axillary sentinel lymph node biopsy may not be performed. For patients with concomitant cancer, the nipple-areola complex and its deeper glands can also be excised + enlarged tumor excision, provided that the breast-conserving criteria are met and the margins are negative, and that axillary sentinel lymph node biopsy or axillary lymph node dissection is performed according to the situation. In conclusion, total mastectomy + surgical axillary staging (sentinel lymph node biopsy or axillary lymph node dissection) is an appropriate option for all patients with Paget’s disease of the breast. For patients with breast-conserving needs, breast-conservation may also be an option if they are eligible, but the need for axillary lymph node management needs to be determined based on preoperative evaluation. The postoperative treatment should be based on the concomitant breast cancer to decide whether to give: endocrine therapy, chemotherapy, radiotherapy, targeted therapy. Note that breast conservation is always treated with radiotherapy (unless there is a contraindication to radiotherapy). There are many studies on the prognosis of Paget’s disease of the breast. Current studies suggest that if one side of the breast has breast cancer, the other side has a higher chance of developing breast cancer than normal. The prognosis of Paget’s disease alone is very good, but the presence of an associated cancer can lead to a worse prognosis, especially if it is an invasive cancer. To summarize: concomitant cancer determines the staging, treatment, and prognosis of patients with Paget’s disease of the breast. Preoperative evaluation and detailed postoperative pathological examination are essential.