CA125, or carbohydrate antigen 125, is a protein that is found on the surface of many ovarian cancer cells and also in the blood of some people with ovarian cancer. CA125 is considered a tumor marker, which means it can be found in higher levels in individuals with certain cancer types, notably epithelial ovarian cancer.
However, it’s important to understand the following about CA125:
- Not Exclusive to Ovarian Cancer: Elevated CA125 levels are not exclusive to ovarian cancer. They can also be found in:
- menstruation,
- pregnancy
- endometriosis
- pelvic inflammatory disease
- liver disease
- other cancers, such as those of the fallopian tube, endometrium, lung, breast, and pancreas
- Not Always Elevated in Ovarian Cancer: Not all ovarian cancers result in elevated CA125 levels. Some women with ovarian cancer may have a normal CA125 level, especially if the cancer is in its early stages.
- Use in Monitoring and Screening: CA125 is frequently used to monitor ovarian cancer treatment, recurrence after treatment, and in some cases, disease progression. When used in combination with transvaginal ultrasound, it has been evaluated as a potential screening tool for ovarian cancer, especially in high-risk populations. However, its use as a primary screening tool in the general population is not currently recommended because of its lack of specificity and sensitivity.
- Use in Combination with Other Markers: Research has explored combining CA125 with other biomarkers to enhance the accuracy of ovarian cancer detection and monitoring.
In summary, CA125 is a tumor marker associated with ovarian cancer, but it’s not exclusive to this cancer, and elevated levels can be seen in various other conditions. It’s essential to interpret CA125 levels in the context of other clinical findings, patient history, and diagnostic imaging.