Cancer Antigen 125 (CA 125), Serum
Use
Cancer antigen 125 (CA 125) is a glycoprotein antigen used to evaluate individuals' response to ovarian cancer therapy and to predict recurrent ovarian cancer. This test is not useful for cancer detection screening in the normal population. Serum CA 125 is elevated in approximately 80% of women with advanced epithelial ovarian cancer. However, the assay sensitivity is suboptimal in early disease stages, with sensitivities of 50% for stage I and 90% for stage II or greater. Elevated serum CA 125 levels have also been reported in various nonovarian malignancies and benign conditions.
Special Instructions
For 12 hours before specimen collection, the patient should not take multivitamins or dietary supplements containing biotin (vitamin B7). If not ordering electronically, complete and send an Oncology Test Request form (T729) with the specimen.
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. Some individuals have antibodies to mouse protein (HAMA), causing interference in immunoassays that employ mouse antibodies. Values obtained with different assay methods cannot be used interchangeably.
New York Approved
Methodology
Immunoassay (ECLIA)
Biomarkers
LOINC Codes
- 83082-8
- 83082-8
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.75 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial.
Patient Preparation
For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements containing biotin (vitamin B7).
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 5 days |
| Frozen | 168 days |