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Mesothelioma Blood Tests and Biomarkers

Mesothelioma biomarkers are proteins that are linked to mesothelioma, an aggressive cancer that develops in the lining of the body’s internal organs. Doctors may use blood tests for mesothelioma to identify biomarkers of this particular cancer, but only a biopsy can confirm a diagnosis. Read more about mesothelioma blood tests and biomarkers, including how we can help you or a loved one get an accurate diagnosis.

Fact-Checked and Updated by: Jenna Tozzi, RN

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What Are Mesothelioma Blood Tests and Biomarkers?

A blood test for mesothelioma is a medical test that analyzes a patient’s blood sample to look for signs of certain biomarkers.

Mesothelioma biomarkers are molecules found in tissues, blood, and other bodily fluids that may be signs of mesothelioma. Biomarkers are sometimes called signature molecules or molecular markers.

The presence of biomarkers does not necessarily mean you have mesothelioma. However, people with certain biomarkers are likely to have mesothelioma. Biomarkers can help doctors distinguish mesothelioma from other diseases when diagnosing this cancer.

We can help get you or a family member in touch with mesothelioma specialists for an accurate diagnosis. Enroll in our Free Doctor Match program today to get started.

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Blood Tests for Mesothelioma

A mesothelioma blood test can show whether you have certain biomarkers that are common in mesothelioma patients. Imaging tests like CT scans can also detect irregular masses or tissue that could be cancerous. However, neither of these methods can confirm the presence of mesothelioma.

The only way to confirm a mesothelioma diagnosis is through a biopsy. This procedure involves removing a tissue or cell sample from your body so it can be tested in a lab. If the tissue is positive for mesothelioma cells, you have mesothelioma. Biopsies can also reveal tissue biomarkers such as calretinin and WT1.

Did You Know?

As of February 2024, the MESOMARK assay (lab test) is the only blood test that’s been approved by the U.S. Food and Drug Administration (FDA) to check for and monitor mesothelioma biomarkers.

What Is the MESOMARK Test?

MESOMARK is a mesothelioma blood test that measures SMRPs in serum, a component of blood. SMRP stands for serum-measured soluble mesothelin-related peptide. SMRPs are created when pieces of mesothelin break off and enter the bloodstream. Mesothelioma cells usually make more mesothelin than healthy cells.

Research has shown that people with mesothelioma have higher SMRP levels. Mesothelioma doctors can use the MESOMARK to monitor biomarkers after diagnosing them with this cancer. However, it is not yet approved to diagnose or detect mesothelioma.

Oncologists may perform other tests to help make a mesothelioma diagnosis, such as positron emission tomography (PET) scans and X-rays. Doctors should only use the MESOMARK blood test to test patients with the epithelial or biphasic mesothelioma cell types. They should not use MESOMARK for patients with sarcomatoid mesothelioma cells.

Learn more about the diagnosis process and get detailed information about this cancer in our Free Mesothelioma Guide, shipped to your door overnight.

How Blood Tests for Mesothelioma Biomarkers Work

Cancer care teams perform a blood test for mesothelioma by following these steps.

  1. Blood Sample Collection: First, your mesothelioma doctor will collect a blood sample by extracting it from a vein. They will then send the sample to a lab for analysis.
  2. Processing the Blood Sample: Lab technicians will process the blood sample by separating the cellular parts from the liquid serum.
  3. Test Sample is Combined With Proteins: The technicians will mix the test sample with unique antibodies or proteins.
  4. Machine Measures Amount of Biomarkers: The technicians will use a machine and computer to determine the amount of biomarkers in the sample. High levels of mesothelioma biomarkers could mean the patient has mesothelioma or another malignant (cancerous) disease.

Is There a Blood Test for Asbestos Exposure?

No, there is currently not an FDA-approved blood test for asbestos exposure, which is the only known cause of mesothelioma. Instead, doctors use imaging scans and biopsies to look for signs of asbestos-related cancer.

While there is not an asbestos blood test, researchers have identified two potential biomarkers for asbestos exposure.

These biomarkers include:

  • 8-OHdG is a molecule linked to asbestos exposure. Cells produce 8-OHdG when they’re damaged by asbestos fibers. People with a history of asbestos exposure have higher than average 8OHdG levels.
  • High mobility group box 1 (HMGB1) is a protein affected by asbestos exposure. Research shows that people exposed to asbestos have higher than normal levels of HMGB1.

In the future, a blood test for asbestos exposure may help doctors diagnose mesothelioma earlier. Many mesothelioma patients may not remember when they were last exposed to asbestos since this cancer can take as long as 50 years to develop.

How Do Biomarkers Affect Mesothelioma Prognosis?

Biomarkers alone may not allow doctors to fully diagnose or detect mesothelioma. However, identifying mesothelioma biomarkers early can help diagnose mesothelioma sooner and help improve a patient’s prognosis (expected outcome, including life expectancy).

The earlier patients receive a mesothelioma diagnosis and treatment, the better their prognosis. This is because aggressive treatments like surgery are generally more effective in early-stage mesothelioma before the cancer spreads.

Unfortunately, certain mesothelioma treatments are less effective against advanced-stage cancer that has spread to other parts of the body.

We can help you or a loved one connect with local mesothelioma specialists for an accurate diagnosis and treatment. Enroll in our Free Doctor Match program to get started.

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Signs of Reliable Mesothelioma Biomarkers

Researchers are continuing to look for reliable mesothelioma biomarkers and prognostic factors.

Generally speaking, mesothelioma biomarkers have the following qualities:

  • Absent in patients who do not have mesothelioma
  • Located in an easily accessible and easy-to-measure body part or fluid, such as saliva or blood
  • Present in patients with mesothelioma

Types of Mesothelioma Biomarkers

There are two main types of mesothelioma biomarkers: tissue biomarkers and non-tissue biomarkers.

Learn more about these two biomarker types below.

Tissue Biomarkers

These are certain biomarkers that are found in samples within the body’s tissues and are usually linked to mesothelioma.

Examples of tissue biomarkers include:

  • Calretinin is a protein that binds calcium that has an important part in many cellular processes. If you test positive for calretinin, there is a high chance you have mesothelioma. However, doctors will need to perform a biopsy to confirm your diagnosis.
  • Cytokeratin 5/6 is a positive marker for malignant pleural mesothelioma. It is found in over 75% of patients. Doctors may use the presence of cytokeratin 5/6 to distinguish distinguish pleural mesothelioma from lung cancer and lung adenocarcinomas.
  • WT1 is a gene that controls the Wilms tumor protein and is often found in higher levels in mesothelioma cells and other malignant cancers.

Non-Tissue Biomarkers

Not all biomarkers are tissue biomarkers. Some may or may not point to a mesothelioma diagnosis.

Examples of non-tissue biomarkers include:

  • Fibulin-3 is commonly found at high levels in pleural mesothelioma patients. Doctors may detect it in biopsy fluid or blood. Teams may use fibulin-3 to distinguish between mesothelioma and other conditions, including benign (non-cancerous) illnesses and other types of cancer.
  • Megakaryocyte potentiating factor (MPF)/n-ERC is another type of protein. Testing has revealed that it is present in mesothelioma patients, but not in the blood of healthy volunteers. Research has suggested that MPF can help researchers distinguish between benign asbestos-related illnesses and cancers like mesothelioma.
  • Serum mesothelin is a blood protein biomarker and is currently considered the best blood protein biomarker of mesothelioma. It is normally found in the lining of major body organs (the peritoneum, pericardium, and pleura). However, the gene expression of serum mesothelin is abnormally high when mesothelioma is present.
  • SMRPs are broken bits of mesothelin. People with a history of asbestos exposure, including mesothelioma patients, have higher SMRP rates than those with no exposure.

Early Detection of Mesothelioma With Blood Testing

Studies have suggested that SMRP blood testing may result in an earlier diagnosis of mesothelioma.

Specifically, the SMRP test has the potential to identify mesothelioma in high-risk individuals with histories of asbestos exposure. This includes people who have worked in asbestos-related industries, such as shipyards and construction workers.

Past research has contributed to this theory. In a study published in The Lancet Oncology journal, researchers took multiple SMRP readings and found that people who developed mesothelioma had elevated SMRP levels.

More specifically, researchers discovered that people who later developed mesothelioma had elevated SMRP levels 1 to 5 years before they were diagnosed. The study also revealed that some asbestos-exposed people have normal SMRP levels throughout the study, and that none of these individuals developed mesothelioma at last follow-up.

Research on Mesothelioma Biomarkers and Testing

Scientists are researching mesothelioma biomarkers in breath testing and CAR T-Cell treatment through clinical trials. They have also identified additional potential biomarkers.

Learn more about these efforts and the results of clinical trials below.

Breath Testing

Scientists have studied molecules in exhaled breath for potential use in diagnosing mesothelioma. If their efforts are fruitful, a breath test for mesothelioma can greatly improve the ease and speed of diagnosis. This technology is promising but requires more research.

Mesothelioma Biomarkers in CAR T-Cell Treatment

A 2021 study published in the journal Cancer Discovery revealed that biomarkers can be used to improve pleural malignant mesothelioma treatment.

In a clinical trial, researchers treated patients with a combination of two immunotherapies:

  • Pembrolizumab (Keytruda®) is a checkpoint inhibitor immunotherapy drug. It interferes with an immune checkpoint protein that may stop immune system cells from killing cancer cells. This drug encourages immune cells to attack tumors by blocking this checkpoint.
  • Mesothelin-targeted CAR T-cell therapy involves taking a sample of the patient’s immune cells and reprogramming them to kill mesothelioma cells by targeting mesothelin. These reprogrammed cells are called CAR T-cells.

The patients who received combination immunotherapy had an overall survival (life expectancy) of 23.9 months. This is significantly higher than the median life expectancy of 13 to 16 months for patients who undergo combination chemotherapy treatment with cisplatin and pemetrexed.

The study results also showed a reduction in serum SMRP levels among the patients enrolled in the trial.

If you’ve been diagnosed with mesothelioma, our Patient Advocates can help you find clinical trials testing immunotherapy and other emerging treatments. Get started today by calling (866) 608-8933.

Emerging Mesothelioma Biomarkers

Besides the ones mentioned above, researchers have found other potential biomarkers that may be detected by a mesothelioma blood test in the future.

Some of these emerging mesothelioma biomarkers include:

  • Epidermal growth factor receptor (EGFR) is a protein that helps cells grow. EGFR mutations can make cells grow too much, leading to cancer. Higher levels of EGFR seem to lead to a poor prognosis.
  • Estrogen receptor beta or NR3A2 is a type of estrogen receptor. In one study, mesothelioma patients with higher estrogen receptor beta levels had higher survival rates.
  • Osteopontin is a protein produced in high quantities by some cancerous tumors. Colon cancer, breast cancer, and lung cancer cells produce a lot of osteopontin. More research must be done before osteopontin can be used as a diagnostic tool.

Get Help Confirming Your Mesothelioma Diagnosis

It’s important to find a specialist immediately if you believe you have mesothelioma. A doctor may use a mesothelioma blood test alongside imaging scans and biopsies to provide an accurate diagnosis.

If you have mesothelioma, your specialist will create a customized treatment plan to improve your prognosis and enhance your quality of life.

Use our Free Doctor Match to get in touch with top mesothelioma doctors in your area.

Mesothelioma Blood Test FAQs

Does mesothelioma show up in blood work?

No, mesothelioma doesn’t show up in routine blood work or standard lab testing.

That said, specific blood tests may be used as part of the diagnostic process and to monitor the disease’s progression or response to treatment. An example of a mesothelioma blood test would be the soluble mesothelin-related peptide (SMRP) test.

Mesothelin is a protein that’s often overexpressed in mesothelioma cells, so the SMRP test measures the levels of this protein in blood. Elevated levels could indicate that the patient has mesothelioma.

What is the cell marker for mesothelioma?

The most specific biomarkers for mesothelioma are serum mesothelin, calretinin, WT1, and cytokeratin 5/6.

If you test positive for these markers, you have a high chance of having mesothelioma. However, doctors can only confirm a mesothelioma diagnosis through a biopsy.

What tests confirm mesothelioma?

A tissue biopsy is the only way to confirm mesothelioma. A biopsy is when doctors take a tissue or cell sample from a suspicious area and test it for mesothelioma cells.

Other tests, including imaging scans and blood tests, may be used to narrow down a possible mesothelioma diagnosis before a biopsy.

Can mesothelioma be detected early?

Yes. It’s sometimes possible to detect a case of mesothelioma early on before it has spread.

Detecting this cancer at an early stage is hard as it takes 10-50 years for symptoms of mesothelioma to appear after asbestos exposure. However, early detection is crucial for better treatment outcomes.

Doctors mainly use imaging tests and biopsies to diagnose mesothelioma. A mesothelioma blood test can assist in the process by showing if there are certain biomarkers present, which could mean you have cancer.

Researchers are continuing to study emerging biomarkers that may help patients be diagnosed in the earlier stages of their cancer.


Jenna TozziWritten by:

Director of Patient Advocacy

Jenna Tozzi, RN, is the Director of Patient Advocacy at Mesothelioma Hope. With more than 15 years of experience as an adult and pediatric oncology nurse navigator, Jenna provides exceptional guidance and support to mesothelioma patients and their loved ones. Jenna has been featured in Oncology Nursing News and is a member of the Academy of Oncology Nurse & Patient Navigators & the American Nurses Association.

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  9. Nadeem, U., & Husain, A. (2021, November 22). Stains & CD markers WT1. Retrieved February 8, 2024, from
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