Breast cancer is the most prevalent cancer among women, but many patients are afraid to seek medical treatment when they feel a breast tumor, and when they first learn that they have breast cancer, they often feel that they cannot face it at all. But please don’t be nervous yet, if you treat stage I breast cancer well, you have a good chance to recover. Let’s learn how to treat stage I breast cancer step by step! When it comes to breast cancer, we have to evaluate two things, one is the tumor itself and the other is the condition of the lymph nodes in the armpit. Stage I breast cancer refers to breast tumor less than two centimeters and lymph node invasion less than two centimeters. The treatment plan for stage 1 breast cancer is mainly “surgery”. Surgery can be divided into two parts, one is the breast tumor and the other is the axillary lymph nodes. In the past, total mastectomy was the main treatment for breast tumors, but nowadays, more and more physicians are considering breast-conserving surgery for stage I breast cancer because the breast tumor is less than two centimeters. However, when the survival rate of breast tumor preservation surgery is comparable to that of total mastectomy, additional radiation therapy is required after surgery. At the same time, the surgeon will choose to treat the lymph nodes depending on the condition. One is to remove the axillary lymph nodes and the other is to test the sentinel lymph nodes. It is important to explain the concept of anterior lymph nodes, which is “lymph node drainage is gradual”. Therefore, in cases where clinical examination does not suspect lymph node metastasis, the physician can first find the first one or two lymph nodes in the patient’s lymphatic drainage by using stains or isotopes, and then take these lymph nodes for testing to see if there is any evidence of cancer metastasis in these lymph nodes. If there is no cancer metastasis in the nearest lymph nodes to the tumor, then we assume that the remaining lymph nodes are healthy and do not need to be surgically removed. If the anterior lymph nodes are determined to have cancer metastasis, then further axillary lymph node contouring surgery will be required. Here, we should remind again that although we explain the surgical treatment into two scopes: tumor and lymph nodes, this is a surgery performed at the same time. The first stage of breast cancer treatment is based on surgery, and it is important to understand the characteristics of the cancer specimen after the surgical removal of the specimen. The pathologists will remove the tissue and test the characteristics of these cancer cells, which are different for each patient. Patients who have Her2 positive cancer cells on the surface can receive targeted therapy. Targeted therapies can target specific cells and have less impact on the patient’s normal cells. Patients who opt for breast-conserving surgery will need additional radiation therapy after surgery, and a small number of patients who undergo total mastectomy will need additional radiation therapy, so please follow your physician’s instructions. If the cancer cells have hormone ER and PR positive receivers on the surface, then hormone therapy can be added to reduce the hormonal stimulation of the tumor. Stage I breast cancer does not necessarily require chemotherapy, but if the physician believes that the tumor is more malignant in nature, chemotherapy may be considered to reduce the recurrence rate of the patient. Overall, the treatment effect of stage I breast cancer patients is very good, with a five-year survival rate of 95% and a ten-year survival rate of over 80%.