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Prostate-Specific Antigen (PSA) with Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) Quantification for Cancer Screening

Published: August 9, 2026Updated: August 17, 2026

This test measures the level of prostate-specific antigen (PSA) in your blood using advanced mass spectrometry technology. PSA is a protein produced by both healthy and cancerous prostate cells, often checked to help screen for prostate cancer.

Quick summary

["PSA screening helps detect early signs of prostate issues, though results alone don’t diagnose cancer."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
19186-6
Short code
CA153-PL
Synonyms
Cancer Ag15-3 Plr-aCnc
Category
chemistry
Sample
fluid
Container
Sterile, leak-proof pleural fluid collection container; transfer to red-top or SST tube for biochemistry analysis
Units
N/A
Ref low
15
Ref high
3
Critical range
0.5 N/A – —
Fasting
false
Population
adult
Sex
female
Age range
≥ 18 years
Method
Immunoassay (chemiluminescent or electrochemiluminescent)
CPT
86316
SNOMED
44608007
Specimen volume
5-10 mL of pleural fluid; minimum 1 mL required for analysis
Stability
Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C): 3 months. Avoid repeated freeze-thaw cycles.
Hemolysis max
100
Lipemia max
100
Icterus max
50
TAT
4–24 hours
Order
routine

Why This Test Is Used

Prostate-specific antigen (PSA) is a protein made by the prostate gland. While it’s normally found in small amounts in the blood, higher levels can signal potential prostate health concerns, including cancer. This test uses a highly sensitive method to measure PSA precisely, which may help identify early changes that could warrant further evaluation.

How the Test Works

Instead of traditional immunoassays, this test uses liquid chromatography-tandem mass spectrometry (LC-MS/MS). This advanced technique separates and identifies PSA molecules with extreme accuracy, reducing interference from other proteins and providing more reliable results.

What to Expect Before the Test

No special preparation is needed, but you may be asked to avoid certain medications (like finasteride or dutasteride) that could affect PSA levels. A blood sample is drawn from a vein, usually in your arm, and sent to the lab for analysis.

What the Results Mean

Results are expressed in nanograms per deciliter (ng/dL). While PSA levels alone don’t confirm cancer, they can guide whether additional testing (like a biopsy) is needed. Your doctor will interpret results in the context of your medical history and symptoms.

Reference range

Pleural fluid CA 15-3 is not routinely used with established reference ranges; serum reference range is typically <30 U/mL. In pleural fluid, markedly elevated values (>100 U/mL) suggest malignant pleural effusion, particularly breast cancer metastasis.N/A

Specimen: fluid

No special patient preparation required for pleural fluid collection. Thoracentesis is performed by qualified healthcare provider under sterile conditions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: PSA Screening in Prostate Health

Short name

PSA Cancer Screening LC-MS/MS

Frequently asked questions

What does a high PSA level mean?
A high PSA level can indicate conditions such as benign prostatic hyperplasia (BPH), prostate inflammation, or prostate cancer. However, many men with normal prostate health have elevated PSA levels, so results must be reviewed by a healthcare provider.
Can PSA levels change over time?
Yes, PSA levels can fluctuate due to age, recent ejaculation, prostate inflammation, or certain medications. Your doctor may track PSA trends over time to assess changes in prostate health.
Is this test the same as a traditional PSA immunoassay?
No, this test uses LC-MS/MS for higher precision, which may detect smaller changes in PSA that traditional methods might miss. It’s particularly useful for screening in men at higher risk for prostate cancer.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy