Laboratory Services

Cancer Antigen 125 (CA 125), Serum

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Updated Test Information:

Test Description
Cancer Antigen 125 (CA 125), Serum
Synonym(s)

CA125 (Cancer Antigen 125); Cancer Antigen 125; Carbohydrate Antigen 125; OV Monitor; Ovarian Cancer-Related Antibodies; Cancer Ag 125 (CA 125), Serum; CA25

Test ID
CA25
General Information

Useful for:



  • Evaluating patients' response to ovarian cancer therapy

  • Predicting recurrent ovarian cancer

  • This test is not useful for cancer detection screening in the normal population.

Specimen Type

Serum

Specimen Requirements

  • Preferred: Serum Gel

  • Acceptable: Red Top

Minimum Sample Volume

0.75 mL

Stability

  • Refrigerated (preferred): 5 days

  • Frozen: 180 days

Limitations

  • Results cannot be interpreted as absolute evidence of the presence or absence of disease.

  • Serum markers are not specific for malignancy and values may vary by method. Values obtained with different assay methods cannot be used interchangeably.

  • Some individuals have antibodies to mouse protein (HAMA), which can cause interference in immunoassays that employ mouse antibodies. In particular, it has been reported that serum specimens from patients who have undergone therapeutic or diagnostic procedures that include infusion of mouse monoclonal antibodies may produce erroneous results in such assays. Rerunning the specimen in question after additional blocking treatment may resolve the issue.

  • No interference was observed from rheumatoid factors up to a concentration of 1200 IU/mL.

  • There is no high-dose hook effect at cancer antigen 125 (CA 125) concentrations of up to 50,000 U/mL.

Methodology

Electrochemiluminescent Immunoassay (ECLIA)

Estimated TAT

1-3 days

Testing Schedule

Monday - Saturday

Retention

3 months

CPT Code(s)

86304

Reference Range

Females: < 46 U/mL

Performing Lab

Mayo

LOINC Code(s)

83082-8

Additional Information