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Serum/plasma mass concentration of cancer-associated antigen 724 (CA724)

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

This test measures a protein produced by certain types of cancerous cells, often used to monitor cancer progression or recurrence.

Quick summary

["Helps track cancer growth or spread in some gastrointestinal cancers."]

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

Key facts at a glance

LOINC
17843-4
Short code
CA72-4
Synonyms
Cancer Ag72-4 SerPl-aCnc
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or red-top tube; plasma may be collected in heparin or EDTA tubes
Units
N/A
Ref low
0
Ref high
6
Critical range
0.5 N/A – —
Fasting
false
Population
adult
Sex
all
Age range
≥ 18 years
Method
Immunoassay (Electrochemiluminescence or Chemiluminescent)
CPT
86316
SNOMED
115327008
Specimen volume
1 mL serum or plasma
Stability
Stable for 24 hours at room temperature; 7 days at 2-8°C; 3 months at -20°C or colder for long-term storage. Avoid repeated freeze-thaw cycles.
Hemolysis max
100
Lipemia max
100
Icterus max
50
TAT
24–72 hours
Order
routine

What Is CA724 Used For?

CA724 is primarily used as a tumor marker in the detection and monitoring of certain cancers, particularly those originating in the gastrointestinal tract, such as stomach, colorectal, or pancreatic cancers. It may also be used in follow-up care to check for signs of cancer returning after treatment.

How Is the Test Performed?

A blood sample is drawn from a vein in your arm. The blood is then processed to separate the serum or plasma, which is sent to a lab for testing. The lab uses a specialized immunoassay method to measure the protein levels in your sample.

Why Might You Need This Test?

Your healthcare provider may order a CA724 test if you have a history of cancer in the gastrointestinal system, are experiencing symptoms like unexplained weight loss, abdominal pain, or changes in bowel habits, or if you are undergoing treatment for cancer to monitor its response.

What Do Results Mean?

Higher than expected levels of CA724 may suggest the presence of cancer or its recurrence. However, it can also be elevated in some non-cancerous conditions, so results should always be interpreted by a healthcare professional in the context of your overall health and medical history.

Reference range

Less than 6 U/mL is generally considered within normal limits; values above 6 U/mL may suggest the presence of malignancy, particularly gastric, ovarian, colorectal, or pancreatic cancer. Reference values may vary by laboratory and assay manufacturer.N/A

Specimen: serum

No fasting required. Inform the clinician of any recent biopsies, surgeries, or inflammatory conditions that may affect results.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: CA724 serves as a biomarker for monitoring certain cancers, particularly those of the gastrointestinal tract. While it can indicate cancer presence, it is not a definitive diagnostic test on its own. Elevated levels may prompt further investigation, including imaging studies or additional tests, to determine the cause and guide treatment decisions.

Short name

CA724 Tumor Marker

Frequently asked questions

Can CA724 levels change with diet or lifestyle?
Diet and lifestyle factors generally do not significantly affect CA724 levels. However, it’s always a good idea to discuss any medications or supplements you’re taking with your healthcare provider before the test, as they may influence results.
How often should I get this test?
The frequency of CA724 testing depends on your medical condition and treatment plan. Your healthcare provider will determine the best schedule based on your individual needs, whether you’re under surveillance for cancer recurrence or managing an ongoing condition.
Are there any side effects from having this blood test?
Most people experience only mild discomfort or bruising at the injection site. Rarely, there may be a slight pinch during the blood draw, but this usually fades quickly. If you experience excessive bleeding, swelling, or signs of infection, contact your healthcare provider.
  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