There are currently two main types of surgery for breast cancer, total mastectomy (radical surgery) and partial mastectomy, or breast-conserving surgery. So what is the difference between these two? We often talk about modified radical breast cancer surgery, which is the surgical procedure that requires complete removal of the breast and is the most commonly used surgical procedure in China, so do all breast cancer patients have to lose their breasts and become young grandmothers? In fact, in Europe and the United States, breast-conserving surgery is the most common procedure chosen by breast cancer patients. What is breast-conserving surgery? Breast-conserving surgery refers to the local excision of breast tumor and the removal of axillary lymph nodes according to the condition, which relatively ensures the integrity of the breast shape and is less invasive. The chance of local recurrence after breast-conserving surgery may be slightly higher than radical surgery, but it does not affect the survival time. Local radiotherapy after breast-conserving surgery can reduce the local recurrence rate to be similar to radical surgery. Therefore, breast-conserving surgery is a surgical procedure that can ensure the safety of treatment while taking into account the patient’s quality of life. Of course, breast-conserving surgery requires certain conditions, mainly related to the size and location of the lump. Breast cancer lumps close to the nipple areola are not suitable for breast-conserving surgery, and breast-conserving surgery is not recommended for lumps that are larger than 3 cm, but the size of the lump is not absolute, and the relative ratio between the size of the lump and the size of the breast needs to be considered. If a breast lump is larger than 3 cm, but the volume of her breast is also larger, and a good breast shape can be preserved after adequate removal of local tissues, breast-conserving surgery can also be considered at this time. Breast-conserving surgery is performed with breast MRI to rule out the presence of small suspicious lesions. During breast-conserving surgery, an intraoperative pathological examination of the incisional margin will be performed to confirm whether there are tumor cells remaining in the incisional margin. If two consecutive positive incisional margin examinations are performed during surgery, breast-conserving surgery should not be continued. After breast-conserving surgery, local radiotherapy is needed to reduce the local recurrence rate of breast cancer.