PSA is the abbreviation of prostate specific antigen, and the normal value of prostate specific antigen is 0~4ng/ml. there is no inevitable connection between high and low prostate specific antigen before surgery and whether it is metastatic or not, and there is a possibility of metastasis if the prostate specific antigen is more than 4ng/ml in 6 weeks after surgery. 1. Before surgery: there is no correlation between the level of prostate-specific antigen and metastasis before surgery, and metastasis cannot be determined by prostate-specific antigen. 2. After surgery: If the tumor is cured after prostate cancer surgery, the prostate-specific antigen in the serum will drop to less than 4ng/ml within 6 weeks. If the tumor is not cured after 6 weeks, and prostate-specific antigen can still be detected in serum, it means that there may be residual tumor, micrometastases or pelvic foci, etc. In general, prostate-specific antigen can be detected in serum after surgery. Overall, prostate-specific antigen is only a judgment indicator for prostate tumor condition, whether metastasis occurs needs to be further judged by CT and other examinations.