What is CA-125 Test? Purpose, Levels, Procedure & Results

The CA-125 test measures a protein called cancer antigen 125 in your blood. This protein can be elevated in various conditions, including ovarian cancer, but it's not exclusive to cancer.

Your doctor might order this test if you have symptoms that could suggest ovarian issues, or they may use it to monitor treatment progress if you've already been diagnosed with certain conditions. Think of it as one piece of a larger puzzle that helps your healthcare team understand what's happening in your body.

What is CA-125?

CA-125 is a protein that your body naturally produces in small amounts. It's found in tissues lining your ovaries, fallopian tubes, uterus, and other organs in your chest and abdomen.

When certain conditions cause inflammation or irritation in these tissues, your CA-125 levels can rise above normal ranges. This elevation doesn't automatically mean cancer - many benign conditions can also cause increased levels.

The protein gets its name from being the 125th antigen discovered in ovarian cancer research. However, elevated CA-125 levels appear in numerous other conditions too, which is why doctors always consider your complete medical picture.

Why is CA-125 test done?

Your doctor typically orders a CA-125 test for several specific reasons. Most commonly, it helps evaluate symptoms that might suggest ovarian or other pelvic conditions.

If you're experiencing persistent bloating, pelvic pain, difficulty eating, or frequent urination, your doctor might use this test as part of their investigation. These symptoms can have many causes, and the CA-125 test provides additional information.

For women already diagnosed with ovarian cancer, doctors use CA-125 testing to monitor how well treatment is working. The levels often decrease when treatment is effective and may rise again if the cancer returns.

Sometimes doctors order this test during routine screening for women at high risk of ovarian cancer, though it's not recommended as a general screening tool for the average person.

What is the procedure for CA-125 test?

The CA-125 test is a simple blood draw that takes just a few minutes. A healthcare professional will insert a small needle into a vein in your arm to collect a blood sample.

You'll feel a quick pinch when the needle goes in, similar to any other blood test. The entire process usually takes less than five minutes from start to finish.

After collecting the blood sample, it's sent to a laboratory where technicians measure the amount of CA-125 protein present. Results typically come back within a few days to a week.

The test itself is quite straightforward - there's no special equipment needed, and you can return to your normal activities immediately afterward.

How to prepare for your CA-125 test?

Good news - you don't need any special preparation for a CA-125 test. You can eat and drink normally before the test, and you don't need to fast.

However, let your doctor know about all medications you're taking, including over-the-counter drugs and supplements. While most medications won't affect the test results, it's always best to keep your healthcare team informed.

If you're menstruating, mention this to your doctor. Your period can slightly elevate CA-125 levels, though this usually doesn't significantly impact the interpretation of results.

Wear comfortable clothing with sleeves that can be easily rolled up, since the blood will be drawn from your arm. This makes the process smoother for both you and the healthcare professional.

How to read your CA-125 test results?

Normal CA-125 levels are typically below 35 units per milliliter (U/mL) for most laboratories. However, the exact normal range can vary slightly between different labs.

If your results show levels above 35 U/mL, this doesn't automatically indicate cancer. Many benign conditions can cause elevated CA-125 levels, and your doctor will consider your symptoms and medical history when interpreting the results.

Very high levels (above 200 U/mL) are more concerning and warrant further investigation. However, even significantly elevated levels can sometimes result from non-cancerous conditions like endometriosis or liver disease.

Your doctor will always interpret your CA-125 results alongside other factors. They'll consider your symptoms, physical examination findings, family history, and possibly order additional tests to get a complete picture.

What causes elevated CA-125 levels?

Several conditions can cause your CA-125 levels to rise above normal ranges. Understanding these various causes can help reduce anxiety while you wait for further evaluation.

Let's look at the different categories of conditions that commonly affect CA-125 levels:

Gynecological conditions:

• Endometriosis - tissue similar to your uterine lining grows outside the uterus
• Ovarian cysts - fluid-filled sacs that develop on your ovaries
• Pelvic inflammatory disease - infection of reproductive organs
• Uterine fibroids - non-cancerous growths in the uterus
• Ovarian, fallopian tube, or primary peritoneal cancers

Other medical conditions:

• Liver disease or cirrhosis
• Heart failure
• Kidney disease
• Lung conditions or infections
• Inflammatory bowel disease
• Pancreatitis

Temporary elevations:

• Menstruation - levels may rise during your period
• Pregnancy - especially in the first trimester
• Recent surgery or medical procedures

This wide range of potential causes explains why doctors never rely on CA-125 results alone to make a diagnosis. They need to consider your complete health picture.

What are the risk factors for elevated CA-125?

Certain factors can increase your likelihood of having elevated CA-125 levels. Being aware of these risk factors helps you and your doctor interpret test results more accurately.

Age plays a significant role - women over 50 are more likely to have elevated levels, particularly if they have a family history of ovarian or breast cancer. Additionally, women who have never been pregnant or who started menstruating early may have higher baseline levels.

Genetic factors matter too. If you carry BRCA1 or BRCA2 gene mutations, you're at higher risk for conditions that can elevate CA-125 levels. Having a family history of ovarian, breast, or colon cancer also increases your risk.

Lifestyle and medical history factors include:

• History of endometriosis or other gynecological conditions
• Previous pelvic infections or inflammatory conditions
• Chronic liver or kidney disease
• Smoking history
• Hormone replacement therapy use

Remember that having risk factors doesn't mean you'll definitely develop elevated CA-125 levels or serious conditions. These factors simply help your doctor assess your individual situation more thoroughly.

What are the possible complications of high CA-125 levels?

High CA-125 levels themselves don't cause complications - they're a sign that points to underlying conditions that may need treatment. The complications you might face depend entirely on what's causing the elevated levels.

If a benign condition like endometriosis or ovarian cysts is causing the elevation, complications are generally manageable. These might include ongoing pelvic pain, fertility issues, or the need for surgical intervention in severe cases.

When elevated CA-125 levels indicate ovarian cancer, the complications become more serious. Early detection and treatment significantly improve outcomes, which is why your doctor takes elevated levels seriously and may recommend additional testing.

The emotional impact of abnormal test results can also be significant. Anxiety about potential cancer diagnosis is completely normal and understandable. Your healthcare team can provide support and clear communication throughout the evaluation process.

When should I see a doctor about CA-125 levels?

You should definitely contact your doctor if you have persistent symptoms alongside elevated CA-125 levels. Don't wait if you're experiencing ongoing pelvic pain, bloating that doesn't improve, or changes in your eating patterns.

Pay attention to symptoms that last more than a few weeks, especially if they're new or different from your usual patterns. These might include feeling full quickly when eating, frequent urination, or unexplained weight loss.

If you have a family history of ovarian or breast cancer and are experiencing any concerning symptoms, it's worth discussing CA-125 testing with your doctor. They can determine if testing is appropriate for your situation.

For women already monitoring CA-125 levels due to a previous diagnosis, follow your doctor's recommended testing schedule. Contact them immediately if you notice any new symptoms or if you're concerned about changes in your condition.