What Is the MESOMARK Blood Test?
The MESOMARK blood test measures the amount of a protein called mesothelin in your bloodstream. Mesothelin is normally present in very small amounts, but mesothelioma cells can release more of it as they grow. Because of this, doctors sometimes use the test to get a better sense of how active the disease may be.
The test isn’t used to confirm mesothelioma, as that can only be done with a biopsy. Instead, this blood test provides supporting information that can help your medical team understand your baseline before treatment starts. Your doctor may use it to see whether your mesothelin protein level is higher than expected and then compare future tests to this starting point.
“A mesothelin test can be helpful, but it’s not required to make a mesothelioma diagnosis. Doctors choose whether to order it based on your symptoms, your asbestos exposure history, and what they already see on your imaging scans.”
Not all mesothelioma patients have elevated mesothelin levels. A normal result doesn’t mean the cancer is gone or in remission. It simply means this particular substance isn’t as useful for tracking your case. If your levels are higher, your care team may check them periodically to monitor how well treatment is working or to watch for changes that may need attention.
Key Facts About the Mesothelin Test
- First approved blood test designed to help doctors diagnose mesothelioma
- Not a standalone diagnostic test, since only a biopsy can confirm cancer
- Often ordered with imaging tests such as CT scans, MRIs, and X-rays
- Useful for tracking the body’s response to mesothelioma treatment
Get our Free Mesothelioma Guide shipped overnight to learn more about the tests used to diagnose this cancer and the latest treatment options available.
What to Expect During the MESOMARK Test
The MESOMARK blood test is quick, simple, and similar to any routine blood draw. You typically do not need to fast or prepare in any special way beforehand.
Here’s what typically happens during the test:
- Blood sample collection: A nurse or technician draws a small amount of blood from a vein in your arm.
- Lab analysis using an ELISA test: The sample goes to a specialized lab, where an enzyme-linked immunosorbent assay (ELISA) test measures the level of soluble mesothelin-related peptides (SMRPs). These SMRPs are proteins shed by mesothelioma cells.
- Results sent to your doctor: Your care team receives a report showing whether your mesothelin level is within the expected range or higher than average.
- Review and follow-up recommendations: Higher mesothelin protein levels do not necessarily mean you have mesothelioma, but they may prompt more testing, such as a CT scan, MRI, or biopsy. Your doctor will explain how your results fit with your symptoms and medical history.
The MESOMARK assay (analysis) is only one of many tests used to help diagnose mesothelioma. If your mesothelin level is higher than expected, your doctor may recommend additional testing to better understand the cause.
If your follow-up imaging or biopsy confirms you have mesothelioma, your doctor will work with you to develop a personalized treatment plan based on your cell type, cancer stage, overall health, and other important factors.
Who Should Get a Mesothelin Test?
A mesothelin cancer test is recommended for people who may have a higher risk of developing mesothelioma. This includes those who have been exposed to asbestos or who are experiencing symptoms that affect the chest or abdomen, where mesothelioma most commonly forms.
Candidates for the MESOMARK blood test include:
- Anyone living near industrial work sites, factories, or mines
- Families of workers who may have been exposed to asbestos secondhand
- Patients with imaging scans that raise concern for cancer
- People with known asbestos exposure, even if it was short-term
- Those with unexplained symptoms like chest pain, breathing issues, or bloating
If you fall into one of these groups, your doctor may order an SMRP test to gather more information before recommending next steps. Depending on the results, your care team may suggest further testing, such as a CT scan or video-assisted thoracoscopic surgery (VATS) to collect tissue samples for biopsy.
How Accurate Is the Mesothelin Test for Mesothelioma?
The mesothelin test is more accurate in diagnosing some types of mesothelioma than others. For example, it is most effective at diagnosing epithelioid mesothelioma, the most common cell type of this cancer. It is less sensitive to sarcomatoid tumors.
Studies published in peer-reviewed research journals show that SMRP has moderate sensitivity but strong specificity. This means higher SMRP levels are more likely to be tied to mesothelioma cases than to other diseases.
Many researchers also test additional serum biomarkers like:
- Fibulin-3
- N-ERC (megakaryocyte potentiating factor / MPF)
- Osteopontin
These biomarkers are being explored in clinical trials to see whether combining them with SMRP can improve early detection and prognostic predictions.
Use our Free Doctor Match service to get help finding a specialist who understands mesothelioma and all available testing options.
Can the Mesothelin Test Detect Mesothelioma Early?
Early detection is vital for mesothelioma patients, as identifying the cancer before it spreads can significantly improve treatment outcomes and life expectancy. Because of this, researchers are actively investigating whether mesothelin testing can help catch the disease sooner.
Current research into this diagnostic tool shows:
- Combining mesothelin testing with other serum biomarkers may improve the chances of early detection.
- In some cases, SMRP levels may rise years before mesothelioma tumors actually develop.
- Not all mesothelioma patients have high mesothelin levels, particularly in the earliest stages of the disease.
- The test is more useful for monitoring those with known asbestos exposure than for screening the general population.
Mesothelin testing may help doctors monitor people at high risk, but it cannot detect mesothelioma early or replace other medical tests.
How Mesothelin Blood Tests Help After Diagnosis
For patients already living with mesothelioma, the mesothelioma protein test can be a helpful part of ongoing treatment planning. Many cancer specialists analyze this information along with imaging scans and patient-reported symptoms to guide their medical decisions.
Doctors may use MESOMARK testing to:
- Assess response to chemotherapy or immunotherapy
- Compare blood test results with scans and symptoms
- Confirm whether the current treatment is effective
- Look for signs that the cancer may be growing or returning
Your medical team will determine whether your SMRP levels are rising, stable, or falling at various points throughout your treatment. The results help them decide if they need to change a dose, add a new medication, or switch approaches entirely.
Hope for Mesothelioma Patients: Get the Right Diagnosis
The MESOMARK blood test can be an important way to help diagnose mesothelioma early and guide you toward the right care. If you or a loved one has a history of asbestos exposure or symptoms of mesothelioma, you’re not alone.
Our nurses and Patient Advocates can help you:
- Find top cancer center specialists
- Understand diagnostic testing options
- Access clinical trials and treatment programs
- Pursue compensation to cover medical costs
- Get support without feeling overwhelmed
Give us a call at (866) 608-8933 or get our Free Mesothelioma Guide shipped overnight to learn more about how we can help your family.
Mesothelin Blood Test FAQs
Will a blood test show mesothelioma?
A blood test cannot confirm whether someone has mesothelioma, but it can provide helpful clues. Mesothelin and other proteins may increase when mesothelioma is developing.
If a blood test shows higher-than-normal levels, your doctor may look more closely with imaging scans or other tests. Think of it as an early signal that something may need more investigation, not a final answer on its own.
What cancers are mesothelin-positive?
Mesothelin is most commonly elevated in mesothelioma, especially the type that forms around the lungs (pleural mesothelioma). However, other cancers can sometimes produce higher mesothelin levels as well.
These include:
- Ovarian cancer
- Pancreatic cancer
- Some lung cancers
Because mesothelin can rise for several reasons, doctors use this result as one part of the bigger diagnostic picture, not as proof of a specific cancer.
Does mesothelioma show up in bloodwork?
Mesothelioma does not show up directly in bloodwork the way some conditions do. Instead, doctors may see changes in mesothelin and other biomarkers that suggest more testing is needed.
Some people with mesothelioma have elevated mesothelin levels, while others never do. For this reason, a blood test can support the diagnostic process but cannot confirm or rule out mesothelioma by itself. Imaging scans and a biopsy are still essential for an accurate diagnosis.
Can the MESOMARK blood test diagnose mesothelioma?
No, the MESOMARK blood test cannot diagnose mesothelioma on its own. Instead, it helps doctors identify whether more testing, such as a biopsy or CT scan, is needed.
High levels of SMRP found through a MESOMARK test could mean you have mesothelioma, especially if you have a history of asbestos exposure, but they don’t confirm cancer. Only a biopsy can provide a definitive diagnosis of mesothelioma.
Why do mesothelin levels become elevated?
Mesothelin levels rise when mesothelioma cells shed proteins into the bloodstream. This happens most often in malignant pleural mesothelioma and especially in the epithelioid cell type.
However, elevated mesothelin does not always indicate mesothelioma. Some other cancers and inflammatory conditions can also increase mesothelin. Doctors interpret the results alongside imaging scans and asbestos exposure history.
What happens if my mesothelin results are high?
If your mesothelin levels are elevated, your doctor will likely order more tests. Common next steps include a CT scan, X-ray, or MRI to look for tumors or abnormalities.
If your imaging scans raise concern, a biopsy will be ordered to confirm a diagnosis. Elevated levels may also prompt referral to a mesothelioma specialist for further evaluation.
If you need help finding a mesothelioma specialist, our team can connect you with top doctors who diagnose this disease every day. Use our Free Doctor Match service to get started.
What lab does the MESOMARK blood test?
The MESOMARK blood test is made by Fujirebio Diagnostics, but it’s not performed in a single location. Instead, the blood sample your doctor collects is sent to a laboratory that has the equipment needed to run this type of test.
These labs use a method called enzyme-linked immunosorbent assay (ELISA) to measure mesothelin levels, which helps your care team understand whether further testing may be needed.
You don’t have to find one of these labs on your own. Your doctor or cancer center will handle the process of sending your sample to a qualified lab. Once the test is complete, the results are sent back to your care team so they can walk you through what the numbers mean and how they fit into your overall diagnosis and treatment plan.
Do insurance plans cover MESOMARK testing?
Most insurance plans cover diagnostic testing recommended by your doctor, including mesothelin blood tests like MESOMARK.
However, coverage varies depending on your insurer, policy, and deductible. If you are concerned about paying for mesothelin testing, our Patient Advocates can help you explore resources for financial assistance.
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