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Test Code CA125 Cancer Antigen 125

Additional Codes

Epic: LAB155

Specimen Required

Collection Conatiner/Tube: Serum SST
Submission Container/Tube: Plastic vial
Specimen Volume: 3.0 mL
Collection Instructions: Centrifuge and separate cells after clot formation and within 4 hours of collection.

Specimen Minimum Volume

1.0 mL

Specimen Stability

Room Temperature: Unacceptable.
Refrigerated on gel: 24 hours
Refrigerated off gel: 7 days
Frozen: >7 days

Reference Range

<35.0 U/mL

Rejection Due To

Specimens stored on gel >24 hours, gross hemolysis

Report Available

Same day

Clinical Significance

CA 125 is a glycoprotein antigen present in tissues derived from ovarian, fallopian, peritoneal, colon, kidney, stomach, and other coelomic tissue.  Increased levels are seen in patients with ovarian and intraperitoneal malignancy; the percentage of positive cases increasing with the cancer stage. CA 125 is also used to assess the effectiveness of ovarian/intraperitoneal cancer treatments and to predict recurrence and prognosis.  Elevated levels of CA 125 may be seen in nonmalignant conditions, first trimester pregnancy, ovarian cysts, pelvic inflammatory disease, and during the menstrual cycle.

Method Name

Chemiluminescent Micro-particle Immunoassay (CMIA)


Patients with Heterophile antibodies (HAMA) may exhibit falsely elevated or falsely depressed results.
CA 125 results should not be used interchangeably with other manufacturers’ methods for CA 125 determinations.  Consistent tube type should be used to collect serial specimens.
CA 125 levels are not useful in screening the general population for cancer.
CA 125 levels should not be used alone as absolute evidence of the presence or absence of malignant disease.  Clinical evaluation and other diagnostic procedures are needed.



Day(s) Performed