The commonly used marker for breast cancer is CA15-3, which is a more classical marker for breast cancer. It is not very sensitive in the early stage of breast cancer, but has a higher positive rate in advanced and metastatic breast cancer. To increase the detection rate, it can be combined with AFP protein and CEA to improve the sensitivity in early stage, and can also add tumor-specific growth factor TSGF, which will be elevated in malignant tumors. In addition, 40% of breast cancers may have elevated CA12-5. It should be reminded that elevated tumor markers do not mean that you have a tumor, and you need to make a comprehensive judgment based on clinical symptoms and some other imaging findings.