CA-125 Blood Test

The CA-125 blood test is a laboratory test used to measure the level of the protein CA-125 (cancer antigen 125) in the blood.

What is CA-125?

CA-125 is a type of protein that is often found on the surface of ovarian cancer cells, as well as some other types of cancer cells. It can also be found in small amounts in the blood of healthy individuals.

Purpose of the Test

The CA-125 blood test is primarily used to:

• Monitor women who have been diagnosed with ovarian cancer to see if the cancer has come back after treatment
• Check for ovarian cancer in women who are at high risk of developing the disease, such as those with a family history of ovarian cancer
• Help diagnose ovarian cancer in women who have symptoms such as bloating, abdominal pain, or difficulty eating

How the Test is Performed

A healthcare provider will take a blood sample from a vein in the arm using a needle and syringe. The blood sample is then sent to a laboratory for analysis.

Interpretation of Results

The results of the CA-125 blood test are usually reported as a number, which represents the level of CA-125 in the blood. A high level of CA-125 can indicate ovarian cancer, but it can also be elevated in other conditions, such as:

• Endometriosis
• Pelvic inflammatory disease
• Uterine fibroids
• Pregnancy
• Miscarriage

Limitations of the Test

The CA-125 blood test is not a definitive diagnostic tool for ovarian cancer. A high level of CA-125 can be caused by other conditions, and some women with ovarian cancer may have normal levels of CA-125. Therefore, the test should be used in conjunction with other diagnostic tools, such as imaging tests and biopsy.

Risk Factors and Screening

The American College of Obstetricians and Gynecologists (ACOG) recommends that women at high risk of ovarian cancer, such as those with a family history of the disease, undergo annual screening with a CA-125 blood test and transvaginal ultrasound. However, routine screening for ovarian cancer is not recommended for women at average risk.