CA125 Use
CA125™ is the most widely used tumor marker worldwide for ovarian cancer and is indicated for use as an aid in the detection of residual ovarian carcinoma in patients who have undergone first-line therapy and would be considered for diagnostic follow-up procedures.
The CA125 test is a blood test that measures the level of the CA125 protein in the blood, which is often found to be elevated in women diagnosed with ovarian cancer. Results of the CA125 test are used to monitor a patient’s response to treatment and for recurrence of disease. The clinical practice guidelines recommend patients be monitored following initial treatment every 2 to 4 months for 2 years, every 6 months for 3 years, and then annually with CA125 (if it was elevated) and a physical examination.14
CA125 is not used to screen for ovarian cancer, because not all women diagnosed with ovarian cancer will have an elevated CA125 value; in addition, some women who have an elevated CA125 value will not have cancer. There are a number of reasons that this occurs. First, there are other conditions that can cause an elevation in the CA125 value. Some of these conditions include menstruation, endometriosis, pregnancy, pelvic inflammatory disease, and benign ovarian cysts. Second, not all tumors express the protein measured by the CA125 assay, and therefore not all tumors will cause an elevation, even in the presence of a malignancy.
There are different formulations of the CA 125 test available in laboratories today. These differences result in variations in the normal range reported by the laboratory. To ensure patients always have a consistent and valid test result, they are encouraged to continue to use the same laboratory for testing.
Benefits of CA125
The CA125 radioimmunoassay is an in vitro diagnostic device for the quantitative measurement of OC125 reactive determinants associated with a high molecular weight glycoprotein in serum of women with primary epithelial invasive ovarian cancer, excluding those with cancer of low malignant potential.
It provides the following benefits
- Early detection of cancer recurrence
CA125 is indicated for use as an aid in the detection of residual ovarian carcinoma in patients who have undergone first-line therapy and would be considered for diagnostic, second-look procedures.
- Enhanced resolution at the low end
A second-generation assay, CA125 II uses the M11 mouse monoclonal antibody as the new capture antibody. The addition of the M11 provides the benefit of increased sensitivity and detection at the low end of the curve, resulting in a clearer diagnostic picture and enhanced early disease detection. The M11 antibody is used in a dual monoclonal, heterogeneous format, enabling an easy, single-step procedure.
- Improved assay variability, clinically validated
CA125 II has been proven in clinical use to provide a reduction in assay variability by approximately 50% over its predecessor marker.15 Utilized in a one-step protocol, CA125 II results in minimal assay interference and inter-assay and intra-assay imprecision of less than 7% and 5% respectively.
- Trusted and accepted by physicians worldwide
Supported by more than 2000 peer-reviewed publications, CA125 II is the most widely used tumor marker worldwide for ovarian cancer and is recommended by the NIH to be a useful diagnostic tool for patient follow-up after surgery. CA125 II is manufactured in a proven, high-quality process, resulting in a consistent and dependable tumor marker assay.
