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Test ID SPSA Prostate-Specific Antigen (PSA) Screen, Serum


Ordering Guidance


Free prostate-specific antigen (PSA) can be added to previously-submitted PSA screen specimen within 72 hours of performing the total PSA. Specimen must have been shipped frozen.

 

If both free and total PSA results are desired, order PSAFT / Prostate-Specific Antigen (PSA), Total and Free, Serum.



Necessary Information


Include patient's age.



Specimen Required


Supplies: Starstedt Aliquot Tube 5mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Red-top tube must be centrifuged, and the serum aliquoted into a plastic vial within 2 hours of collection.

2. Serum gel tube must be centrifuged within 2 hours of collection.


Secondary ID

82023

Useful For

As a screening aid in the detection of prostate cancer when used in conjunction with a digital rectal exam in men 50 years or older

 

Screening to aid in the prognosis and management of individuals diagnosed with prostate cancer

Method Name

Electrochemiluminescent Immunoassay

Reporting Name

Prostate-Specific Ag Screen, S

Specimen Type

Serum

Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Frozen (preferred) 180 days
  Refrigerated  5 days

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.

 

In patients with previously diagnosed prostate cancer, PSA testing is advocated as an early indicator of tumor recurrence and as an indicator of response to therapy. The role of PSA in early detection of prostate cancer is controversial. The American Cancer Society recommends annual examination with digital rectal examination and serum PSA beginning at age 50 and for men with a life expectancy of at least 10 years after detection of prostate cancer. For men in high-risk groups, such as African Americans or men with a first-degree relative diagnosed at a younger age, testing should begin at a younger age. It is generally recommended that information be provided to patients about the benefits and limitations of testing and treatment so they can make informed decisions.

Reference Values

Males:

Age (years)

PSA upper limit (ng/mL)

<40

≤2.0

40-49

≤2.5

50-59

≤3.5

60-69

≤4.5

70-79

≤6.5

≥80

≤7.2

 

Females: Not applicable

Cautions

Serum markers are not specific for malignancy, and values may vary by method.

 

When age is not supplied, the results cannot be flagged as high or low.

 

Digital rectal examination generally does not increase normal prostate-specific antigen (PSA) values. However, cystoscopy, urethral instrumentation, and prostate biopsy may increase PSA levels.

 

In rare cases, some individuals can develop antibodies to mouse or other animal antibodies (often referred to as human anti-mouse antibodies [HAMA] or heterophile antibodies), which may cause interference in some immunoassays. The presence of antibodies to streptavidin or ruthenium can also rarely occur and may interfere in this assay. Caution should be used in interpretation of results, and the laboratory should be alerted if the result does not correlate with the clinical presentation.

 

Serum biotin concentrations up to 1200 ng/mL do not interfere with this assay. Concentrations up to 1200 ng/mL may be present in specimens collected from patients taking extremely high doses of biotin up to 300 mg per day.(1) In a study among 54 healthy volunteers, supplementation with 20 mg/day biotin resulted in a maximum serum biotin concentration of 355 ng/mL 1 hour post-dose.(2)

Day(s) Performed

Monday through Saturday

Report Available

1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

84153

G0103 (if appropriate)

NY State Approved

Yes