Cancer Antigen-Breast (CA 15-3)
Also known as: CA-BREAST
Use
The Cancer Antigen-Breast (CA 15-3) test is primarily used for monitoring therapy and identifying disease recurrence in individuals with metastatic breast cancer. It is not recommended for the diagnosis or screening of breast cancer. Patients undergoing treatment for Stage II and III breast cancer may benefit from this test, as it provides a quantitative measure of CA 15-3 levels that can indicate changes in disease status. Serial measurements are utilized in conjunction with other clinical assessments to monitor the progression of breast cancer. However, elevated CA 15-3 levels can also occur in nonmalignant conditions, hence the results should be interpreted cautiously and not used as stand-alone evidence for malignant disease.
Special Instructions
This test is approved in New York state. Serum or plasma should be collected in a separator tube (serum or plasma separator tube).
Limitations
The CA 15-3 test results are method-dependent, meaning results obtained through different methods or kits cannot be compared or used interchangeably. While the test is useful in monitoring known breast cancer cases, patients with confirmed carcinoma may have CA 15-3 values akin to those found in healthy individuals. Additionally, elevations in CA 15-3 levels may also be present in patients with certain nonmalignant diseases, which limits its specificity and diagnostic utility. Therefore, CA 15-3 levels alone should not be relied upon for determining the presence or absence of malignant breast cancer.
FDA ApprovedNew York Approved
Methodology
Immunoassay (ECLIA)
Biomarkers
LOINC Codes
- 6875-9
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Allow specimen to clot completely at room temperature. Separate serum or plasma from cells as soon as possible or within 2 hours of collection. Transfer 1 mL serum or plasma to an ARUP Standard Transport Tube.
Storage Instructions
Refrigerate the specimen after separation from cells.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 5 days |
| Frozen | 3 months |