Squamous cell carcinoma antigen is a tumor glycoprotein-related antigen isolated from squamous epithelial cell carcinoma of the uterine cervix, which has high specificity for most squamous epithelial cell carcinomas. The level of squamous cell carcinoma antigen is related to the progression and clinical stage of patients with squamous cervical carcinoma, and the squamous cell antigen will increase significantly if the tumor invades the lymph nodes. When the patient is completely treated and cured, the level of squamous cell antigen will continue to decrease. When squamous cell antigen continues to rise after chemotherapy, it indicates that this chemotherapy regimen is not sensitive and should be replaced by other chemotherapy regimens and treatments.