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HelpTest Code LAB171 Prostate-Specific Antigen (PSA), Free and Total, Plasma or Serum
Reporting Title
PSA Free (II)
Methodology
Roche Diagnostics, Electrochemiluminescence Immunoassay
Note: Do not order LAB116 “Prostate-Specific Antigen (PSA) Screen, Plasma or Serum” with this test.
Includes free and total PSA.
Results from assays produced by different manufacturers may not be comparable
Useful For
This assay measures free, uncomplexed PSA. Free PSA has been found to comprise a significantly smaller fraction of PSA in patients with untreated prostate cancer than in patients with benign prostate hypertrophy. This assay is most useful for patients whose total PSA is in the range of 4.0 ng/mL to 10.0 ng/mL.
Performing Laboratory
OhioHealth Laboratory Services-RMH Core Laboratory
Specimen Requirements
Due to interference, patients receiving high doses of biotin (>5 mg/day) should wait at least 8 hours after dose before having blood drawn.
Collection Instructions:
1. Serum and Plasma gel tubes should be centrifuged within 2 hours of collection.
2. Red-top tubes should be centrifuged and aliquoted within 2 hours of collection.
Submit only 1 of the following specimens:
Preferred:
Serum
Draw blood in a gold-top serum gel tube(s). Spin down and send 1 mL of serum refrigerated.
Note:
1. A speckled-top serum gel tube (s) or a plain, red-top tube(s) is also acceptable.
2. Specimen should be drawn before biopsy, digital rectal examination, prostatectomy, or prostate massage since manipulation of prostate may lead to elevated PSA levels persisting up to 3 weeks.
3. Patients receiving therapy with mouse monoclonal antibodies may have erroneous results.
4. Indicate serum on request form.
5. Label specimen appropriately (serum).
Alternate:
Plasma
Draw blood in a mint green-top (heparin) gel tube(s) or a lavender-top (EDTA) tube(s). Spin down and send 1 mL of heparinized or EDTA plasma refrigerated.
Note: 1. Specimen should be drawn before biopsy, digital rectal examination, prostatectomy, or prostate massage since manipulation of prostate may lead to elevated PSA levels persisting up to 3 weeks.
2. Patients receiving therapy with mouse monoclonal antibodies may have erroneous results.
3. Indicate plasma on request form.
4. Label specimen appropriately (plasma).
Specimen Stability Information
TOTAL PSA
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum or plasma | Refrigerated | 5 days |
| Ambient | ||
| Frozen | 6 months |
Specimen Stability Information
Free PSA
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum or plasma | Refrigerated | 3 days |
| Ambient | 8 hours | |
| Frozen | 3 months |
Specimen Transport Temperature
Refrigerate/Frozen OK/Ambient NO
Reference Values
TOTAL PSA- Recommended guidlines from the National Cancer Comprehensive Network (NCCN), 2016
PSA 0.00-0.99 ng/mL for ages ≤ 75
PSA 0.00-3.00 ng/mL for ages >75
All PSA results will flag as high in men age 75 and younger with an interpretive comment based on age and PSA value. The comment will list the recommendation of the NCCN.
The new recommendations put forth by the NCCN are to obtain a baseline PSA level for men age 45-75. The frequency of subsequent screening is dictated by the baseline result. If the result is <1.0 ng/mL, repeat testing every 2-4 years. If the result is between 1.00-3.00 ng/mL, repeat testing every 1-2 years. PSA values >3.00 ng/mL are considered positive regardless of age. PSA testing in men over 75 should only be considered in very select patient. Very few men in this age group benefit from PSA screening.
FREE PSA
No established reference values
%FREE PSA (Only reported if Total PSA is in the range of 4.0-10.0 ng/mL)
Based on data from various clinical trials, a cutoff value of 25% FPSA is recommended. 95% of prostate cancers are associated with %FPSA values of <25%. Higher total PSA levels and lower percentages of free PSA are associated with higher risks of cancer.
Serum markers are not specific for malignancy, and values may vary by method.
Note: A low result following cancer treatment which includes hormonal therapy may not reflect the presence of residual or recurrent disease.
Day(s) Test Set Up
Monday through Sunday; Continuously
Test Classification and CPT Coding
84153 - PSA, total
84154 - PSA, free