PROSTATE SPECIFIC ANTIGEN (PSA) - (P)
Test Code: PRSA
Prostate-specific antigen (PSA) is a glycoprotein produced by the prostate gland, lining of the urethra and the bulbourethral gland. Very little PSA is normally present in the blood. Increases in glandular size, tissue damage caused by benign prostatic hypertrophy, prostatitis or prostate cancer may increase circulating PSA levels.
PSA testing is used to monitor patients with a history of prostate cancer as an early indicator of recurrence and response to treatment. The role of PSA in early detection of prostate cancer is controversial.
The decision whether or not to pursue screening should be based on shared decision-making after the potential benefits and harms associated with screening have been discussed with the patient.
Patient Preparation Instructions: Multivitamins (45–125 µg biotin) or biotin-only supplements up to 1 mg per day do not interfere with this test. Samples should not be taken from patients receiving therapy with high biotin doses (i.e. >5 mg/day) until at least 8 hours after the last dose.
Additional Information: The test method used is an Electrochemiluminescence (ECLIA) assay manufactured by Roche Diagnostics Inc. and performed on the Cobas Elecsys system.
Patient results determined by different assay manufacturers or methods are not comparable and cannot be used interchangeably for patient monitoring.
Plasma: 2.0 mL
Stability 5 days refrigerated, 6 months frozen
Serum: 2.0 mL
Samples must be transferred to an aliquot tube and stored frozen if analysis will not be complete within 48 hours (#110-10-05 Serum / Plasma Separation Procedure & Transport)
< or = 49 y: <2.5 μg/L
50-59 y: <3.5 μg/L
60-69 y: <4.5 μg/L
> or = 70 y: <6.5 μg/L