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.

Frequently Asked Questions (FAQs)

What is the CA-125 blood test used for?
The CA-125 blood test is primarily used to monitor ovarian cancer and its treatment, but it can also be elevated in other conditions.

What does the CA-125 test measure?
The test measures the level of the protein CA-125 in the blood.

Is a high CA-125 level always indicative of cancer?
No, high levels can be caused by non-cancerous conditions such as endometriosis, pregnancy, and pelvic inflammatory disease.

Can a low CA-125 level rule out ovarian cancer?
No, some women with ovarian cancer may have normal CA-125 levels.

How is the CA-125 blood test performed?
The test involves a simple blood draw from a vein in the arm.

Are there any preparations needed for the CA-125 blood test?
Typically, no special preparation or fasting is required before the test.

What are normal CA-125 levels?
Normal levels typically range from 0 to 35 units per milliliter, but this can vary slightly between laboratories.

How often is the CA-125 test repeated?
The frequency of testing depends on the individual's medical condition and their doctor's recommendations.

Can the CA-125 test be used for screening asymptomatic women for ovarian cancer?
The test is not recommended as a routine screening test for asymptomatic women due to its limitations in detecting early-stage ovarian cancer.

What other tests may be used in conjunction with the CA-125 test?
Other tests such as ultrasound, CT scans, and biopsy may be used to confirm a diagnosis of ovarian cancer or to monitor treatment.