PSA sanding disc  stands for prostate specific antigen, which is mainly produced by the epithelial cells of the prostate gland proteolytic enzyme, under normal circumstances, be secreted into the prostatic fluid or semen to the active free form (f-PSA) present in serum the PSA exists mainly in bound form, usually in the f-PSA and complexed PSA and the total PSA (t-PSA) on behalf of serum total PSA levels of serum PSA measurement accuracy is high, stable, reproducible, and is non-invasive helps prostate cancer early diagnosis, monitoring response to treatment and prognosis. Also be used for high-risk groups (men over 50) of prostate cancer screening.
Serum PSA absolutely partly from the prostate, with organ specificity. PSA is a prostate-specific antigen, but not prostate cancer specific antigen, normal and benign prostatic hyperplasia prostate epithelial secretion may PSA, so patients with elevated PSA on the clinical decision-making should be carefully treated differently.