Prostate-specific antigen (PSA) is a glycoprotein produced by the epithelial cells lining the prostatic ducts and acini. Normally, it is secreted into the prostatic ducts and is present only in prostate tissue, prostatic fluid, and seminal plasma. PSA is produced by normal, hyperplastic, and cancerous prostatic tissue. PSA is used as a tumor marker for the early detection of prostate cancer and in other areas of prostate disease management.
PSA sampling should not be performed for at least six weeks after prostatic biopsy. This test is intended for use as an aid in the management of patients following surgical or medical treatment for prostate cancer. Values obtained with different assay methods should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor each patient's course of therapy.
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R).
It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Gold serum separator (SST) tube
Red: Spin and separate
Lt green: Spin
Ambient (preferred) - 7 days
Refrigerated - 7 days
Frozen - 14 days
Electrochemiluminescence Immunoassay (ECLIA)
Male: 0.000-4.000 ng/mL
According to the American Urological Association (AUA), serum PSA should decrease and remain at undetectable levels after radical prostatectomy. The AUA defines biochemical recurrence as an initial PSA value ≥0.20 ng/mL followed by a subsequent confirmatory PSA value ≥0.20 ng/mL.