I. Screening time for breast cancer should be advanced to 25 years old Many doctors in outpatient clinics have come into contact with patients who have breast tumors in their 20s, so it is recommended that the age of breast screening should be advanced, i.e., once every three years from the age of 25 for breast specialist examination; once a year for breast examination from the age of 35. Among them, patients with family history of tumor or high risk factors such as precancerous lesions should be changed to one examination every six months. Because early screening can advance the age of breast cancer diagnosis for young women by 2 years. Currently, breast cancer screening mainly consists of ultrasound and mammography. Breast cancer screening methods should be chosen according to age. Breast self-examination can only be used as a supplementary diagnosis, and the doctor’s examination should be the main focus. In young women, because of the dense breast gland, mammography is easy to miss and may induce breast cancer, so ultrasound is recommended for women under 35 years old. Women over 35 years old should have one mammogram; over 40 years old should have one mammogram every year. Early Self-Detection Breast lumps are the main symptom that prompt patients to seek medical consultation. 80% of the lumps are discovered by patients themselves accidentally, and only a small percentage is discovered by doctors during physical examination. The majority of lumps are located in the upper outer quadrant of the breast, followed by the upper inner quadrant, upper and central regions, and less frequently in other areas. The shape of the lump is usually irregular, but it may be round or oval. In obese patients or those with masses located deep in the posterior part of the breast, the masses are often flat and lamellar or have a limited glandular thickening, with an unsmooth or granular surface and unclear borders. However, it should be noted that the smaller the lump is, the less obvious the above features are. In addition, for some special types of cancer, even larger lumps may show clearer borders and better mobility due to lighter infiltration. The texture of the mass is not exactly the same, but mostly solid, hard or even stone-like. However, medullary carcinoma and lobular carcinoma, which are rich in cells, are often soft, mucinous carcinoma is tough, and cystic papillary carcinoma is cystic in shape with fluctuating sensation. A few small carcinomas occurring in fatty breasts (mostly in the elderly) give the impression of soft surface when palpated because they are surrounded by fat. Mobility Compared with benign lumps, its mobility is poor. 2. Nipple overflow The incidence of nipple overflow in breast cancer is low. However, it is rare for breast cancer to have nipple overflow as the only symptom, and most of them are accompanied by breast lumps. Most of them are accompanied by breast lumps. Malignant intra-ductal papilloma and eczema-like carcinoma of the nipple can also be accompanied by nipple overflow. In breast cancer, the overflow is usually seen in a single ductal opening of a single breast. The overflow can be spontaneous or passive by squeezing, and its nature is mostly bloody, plasma blood or watery overflow. When the cancer invades the nipple or the areola, the fibrous tissue and duct system of the breast may contract due to tumor invasion, pulling the nipple and making the nipple deviate to the tumor-side, and further development of the lesion may make the nipple flattened, retracted and sunken until the nipple is completely retracted under the areola. 4.Local skin changes Depending on the early or late stage of breast cancer, different skin changes may occur. Some superficial early cancers can invade the suspensory ligament of breast and make it contracted, or the tumor can adhere to the skin and make the skin sunken, and the cancer cells can block the subcutaneous lymphatic vessels and make the skin edema. The tumor cells can block the subcutaneous lymphatic vessels, which can lead to skin edema and “orange peel-like changes”. If the tumor invades the lymphatic vessels in the skin, small cancer foci can be formed around the tumor, which is called satellite nodules, and if most of the small nodules are distributed in pieces, it will be shaped as “armor-like changes”. In advanced cancer patients, the skin may be completely fixed or even broken, showing cauliflower-like changes, which will not heal after a long time. In inflammatory breast cancer, the local skin is inflammation-like, with color ranging from light red to dark red, which is limited at the beginning but will soon expand to most of the breast skin, accompanied by skin edema, thickened and rough skin to touch, and increased skin temperature, which is similar to mastitis during pregnancy and lactation, so clinical attention should be paid to differentiation. 5.Breast contour change Due to tumor infiltration, the curvature of the breast may change and appear slightly convex or concave. It can also be seen that the breast is elevated, so that both nipples are not at the same level. 6. Axillary and supraclavicular lymph nodes A breast lump with large, hard and less mobile lymph nodes in the axilla and supraclavicular fossa, or fused with each other, indicates a high possibility of metastasis. It is worth noting that occult breast cancer often has enlarged axillary or supraclavicular lymph nodes as the first symptom, while the primary lesion in the breast is small and difficult to be detected clinically.