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HelpTEST ID PSAFT Prostate-Specific Antigen (PSA), Total and Free, Serum
Reporting Name
PSA Total and Free, SSpecimen Type
SerumOrdering Guidance
This test may be ordered for patients undergoing evaluation of suspicion of prostate cancer, or for assessing the risk of prostate cancer in patients with borderline or moderately increased total prostate-specific antigen (4.0-10.0 ng/mL).
Necessary Information
Include patient's age.
Specimen Required
Supplies: Sarstedt Aliquot Tube 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL serum
Collection Instructions: Within 3 hours of collection, centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
Serum: 0.75 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Frozen (preferred) | 90 days |
| Refrigerated | 72 hours |
Testing Algorithm
Total prostate-specific antigen (PSA) and free PSA are performed and reported on every specimen.
If the initial total PSA concentration is between 4.0 and 10.0 ng/mL, then the percentage of free PSA will be calculated and reported.
Method Name
Electrochemiluminescent Immunoassay (ECLIA)
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | Reject |
Day(s) Performed
Monday through Saturday
Report Available
1 to 3 daysSpecimen Retention Time
14 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
84153
84154
Forms
If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:
-General Request (T239)
-Oncology Test Request (T729)
Useful For
As an aid in distinguishing prostate cancer from benign prostatic conditions in men aged 50 years and older with total PSA between 4.0 and 10.0 ng/mL with digital rectal examination findings that are not suspicious for cancer
Clinical Information
Prostate-specific antigen (PSA) is a glycoprotein produced by the prostate gland, the lining of the urethra, and the bulbourethral gland. Normally, very little PSA is secreted in the blood. Increases in glandular size and tissue damage caused by benign prostatic hypertrophy, prostatitis, or prostate cancer may increase circulating PSA levels.
PSA exists in serum in multiple forms: complexed to alpha-1-anti-chymotrypsin (PSA-ACT complex), unbound (free PSA), and enveloped by alpha-2-macroglobulin (not detected by immunoassays).
Higher total PSA levels and lower percentages of free PSA are associated with higher risks of prostate cancer.
Most prostate cancers are slow growing, so the utility of prostate cancer screening is marginal in most men with a life expectancy of less than 10 years.
Highlights
In individuals with a total prostate-specific antigen (PSA) concentration between 4.0 and 10.0 ng/mL, free PSA:total PSA ratio could help determine the relative risk of prostate cancer. The lower the free PSA:total PSA ratio, the higher the risk of prostate cancer.