Breast cancer is one of the most common malignant tumors in women, occurring mostly in women around the age of 40-60 years old during menopause. It also occurs in men between the ages of 50-60. The first symptom is a painless lump in the breast, which is usually found unintentionally or during physical examination. The first symptom is a painless lump in the breast, which is usually found unintentionally or during physical examination. In a few cases, the lump may be painful and occurs in the upper outer quadrant of the breast. In a smaller number of patients, the first symptom is nipple discharge, nipple erosion or nipple retraction. A small number of patients will have axillary lymph node metastases or other systemic hematologic metastases prior to the discovery of the primary focus. When the lump gradually increases in size, there will be obvious symptoms such as dimpling of the skin on the surface of the lump, “dimple syndrome”, nipple depression due to invasion of the nipple, and “orange peel” when the skin is edematous with many dotted holes in the hair follicles. In contrast, the main symptom of male breast cancer is a lump in the breast. Since male breasts are smaller, tumors tend to invade the skin and pectoral muscle at an early stage, resulting in “dimples”, “orange peel”, and “armor-like” symptoms. Lymph node metastasis also occurs earlier and satellite nodes are easily formed. Although the early symptoms of breast cancer are not obvious, it is important for everyone to be aware of the need for frequent personal checkups to detect and screen for the disease on their own.