What’s the CA-125 test?

Print anything with Printful



The CA-125 test measures the concentration of CA-125 in the blood, which is a tumor marker that can indicate the presence of cancer. While high levels are associated with ovarian cancer, they can also be caused by other cancers and diseases. The test is not ideal for screening ovarian cancer, but it is useful in detecting recurrence in selected patients.

The cancer antigen 125 (CA-125) test is a laboratory study done to evaluate the concentration of CA-125 in the blood. This molecule is considered a tumor marker because a high concentration in the blood can signal the presence of an underlying cancer. While high levels are most closely associated with ovarian cancer, they can also be caused by other cancers and diseases. The test is not an ideal screening test for ovarian cancer, but it has an important role in detecting recurrence of ovarian cancer in selected patients.

CA-125 often serves as an indicator that cancer is present in the body. Malignant growths, including ovarian cancer, produce this substance and shed it into the bloodstream. Concentrations in the blood above 35 units per milliliter are suspicious due to the presence of underlying cancers. About 80% of women with ovarian cancer have a level that exceeds this threshold.

As mentioned above, CA-125 elevations are most closely associated with ovarian cancer. Other cancers, including those that arise from the breast, lung, pancreas, and uterus, can also cause high concentrations of this substance. It is generally considered a marker of epithelial cancer, which is a category of malignancies that arise from cells lining different organs in the body.

Although CA-125 elevations are most commonly seen in people with cancer, other conditions can also cause elevated levels. Patients with diseases such as endometriosis, inflammatory bowel disease, benign ovarian cysts, pelvic inflammatory disease and cirrhosis of the liver may have high levels of this substance. Some women also have variations in the blood concentration of this molecule during their menstrual cycles.

Many researchers have tried to use the CA-125 blood test as a method to screen for the presence of ovarian cancer, but this practice has not become widespread for a variety of reasons. First, not all women with ovarian cancer have abnormalities in this blood test. Using the test for screening purposes may not identify more than 20% of women with ovarian cancer. Second, the test elevation may be caused by non-malignant conditions. Women who experience elevations on testing for benign reasons may be under the stress of a possible cancer diagnosis and would also have to bear the expense and inconvenience of further more extensive testing for ovarian cancer.

Measurement of CA-125 plays an important role in monitoring women recovering from ovarian cancer. After being treated with surgery, radiation, and chemotherapy to eradicate the tumor, patients may be in remission and show no clinical evidence of persistent disease. Subsequent regrowth of cancerous cells can cause the level of CA-125 to rise, signaling that the cancer may come back.




Protect your devices with Threat Protection by NordVPN


Skip to content