Glycoantigen CA153 is secreted by epithelial cells with secretory function, such as breast, lung, gastrointestinal tract, uterus, etc. It can also be detected in excreta of normal people. Therefore, glycoantigen CA153 as a tumor marker may be elevated in breast, lung, ovarian, and gastrointestinal tumors, but is more pronounced in breast cancer. The clinical significance of glycoantigen CA153 is as follows: i. Patients with breast cancer can have significantly elevated CA153, so it can be used to assist in the diagnosis of breast cancer. Second, it can be used as an indicator of postoperative efficacy observation and prognosis judgment of breast cancer, and has important value for the diagnosis of recurrence and metastasis. Other malignant tumors also have a certain positive rate, such as lung cancer, colon cancer, ovarian cancer, uterine cancer, etc. Fourth, normal people may also have mildly elevated cases.