From the Guidelines
Breast cancer markers that can be tested by blood include CA 15-3 and CA 27.29, which are used for monitoring treatment response and detecting recurrence in patients already diagnosed with breast cancer. Several studies have shown that these markers can predict recurrence an average of 5 to 6 months before other symptoms or tests 1. However, it is essential to note that these markers are not recommended for screening, diagnosis, or staging of breast cancer due to insufficient evidence of their clinical benefit in these settings 1.
When considering the use of these markers, it is crucial to understand their limitations and potential false positives or negatives. For instance, an increasing CA 15-3 or CA 27.29 level may indicate treatment failure, but caution should be used when interpreting a rising level during the first 4 to 6 weeks of a new therapy, as spurious early rises may occur 1.
Some key points to consider about these markers include:
- CA 15-3 and CA 27.29 are well-characterized assays that allow the detection of circulating MUC-1 antigen in peripheral blood 1
- These markers may have prognostic value, but their role in the management of early-stage breast cancer is unclear 1
- They can be used in conjunction with diagnostic imaging, history, and physical examination for monitoring patients with metastatic disease during active therapy 1
- However, they should not be used alone for monitoring response to treatment, and their use should be interpreted with caution 1
In summary, while CA 15-3 and CA 27.29 can be useful tools for monitoring treatment response and detecting recurrence in patients with established breast cancer diagnoses, their use should be guided by a thorough understanding of their limitations and potential applications, as supported by the most recent and highest quality evidence 1.
From the Research
Breast Cancer Markers Testable by Blood
The following breast cancer markers can be tested by blood:
- CA 27.29 2, 3, 4
- CA 15-3 3, 5, 4
- CEA (Carcinoembryonic Antigen) 5, 4
- Alkaline phosphatase 6
- SGOT (Serum Glutamic-Oxaloacetic Transaminase) 6
- Gamma-GT (Gamma-Glutamyl Transferase) 6
Sensitivity and Specificity of Markers
The sensitivity and specificity of these markers vary:
- CA 27.29: sensitivity of 25.5% in breast cancer patients, and 85.7% in patients with metastatic disease 4
- CA 15-3: sensitivity of 24.1% in breast cancer patients, and 82.8% in patients with metastatic disease 4
- CEA: sensitivity of 18.6% in breast cancer patients, and 62.8% in patients with metastatic disease 4
- Alkaline phosphatase: effective in distinguishing patients with relapse from those without relapse, particularly for bone and liver metastases 6
Association with Clinicopathological Parameters
These markers are associated with various clinicopathological parameters: