What Is Mesothelioma?

Is mesothelioma cancer? Mesothelioma is a rare group of cancers typically caused by inhaling or swallowing airborne asbestos fibers. Malignant mesotheliomas are cancers that primarily start in the mesothelium of the pleura (chest cavity), peritoneum (abdominal cavity), pericardium (heart cavity).

Can you survive mesothelioma? Life expectancy after diagnosis (commonly referenced as a five-year survival rate) is generally poor; about 46 percent of patients are alive one year after being diagnosed. This is why early detection is so important.

Mesothelioma Statistics

  • Mesothelioma tumors can take 20 to 50 years to develop and cause noticeable health complications. Early signs of the disease often include symptoms like chest pain, shortness of breath, and/or fluid buildup.
  • Pleural mesothelioma affecting the lining of the chest cavity is the most common type – accounting for up to 85 percent of mesothelioma cases.
  • Men make up the majority of cases due to occupational exposure to asbestos in fields like construction.
  • The average age of people diagnosed with pleural mesothelioma in the U.S. is 72 years old.

Symptoms of Mesothelioma

The early symptoms of mesothelioma are often the same as less-severe diseases, causing many people to overlook the signs of a major health problem. Additionally, most patients diagnosed with mesotheliomas had symptoms for several months prior to seeing a doctor for testing.

In general, mesothelioma symptoms include a fever, fatigue, excessive sweating, blood clots, loss of appetite, and unexplained weight loss. Specific symptoms depend on the location of the growing mesothelioma tumors.

Location of Mesotheliomas Symptoms
Pleural mesothelioma Chest pain or lower back pain, shortness of breath, persistent cough, difficulty swallowing, hoarse voice, swelling of the face and/or arms
Peritoneal mesothelioma Swollen belly, abdominal pain, nausea, vomiting, constipation
Pericardial mesothelioma Chest pain, irregular heartbeat, heart murmur, shortness of breath

Asbestos causes latent mesothelioma. Think you were exposed? Request a case evaluation to pinpoint the cause and who’s responsible.

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Cancerous cells form when the DNA of healthy cells is damaged. While the exact mechanisms that cause mesothelioma are not yet clear to cancer researchers, asbestos exposure is recognized as the primary cause of pleural mesothelioma. Approximately 80 percent of people diagnosed with mesothelioma have been exposed to asbestos at some time in their lives.

When asbestos enters the body (often in the form of dust from loose fibers), the small particles travel deep into the ends of respiratory pathways. There, the particles become lodged in the pleura surrounding the lungs, causing inflammation and tissue scarring. If swallowed, the toxins can travel through the digestive system into the peritoneum lining the abdominal cavity.

Radiation therapy has been studied as another possible cause of certain types of mesothelioma. Even the kinds of radiation used in cancer treatments can lead to mutations in cells’ DNA. Eventually, these mutations may spread, resulting in cancer.

Who’s at Risk?

Certain groups of people are at a higher risk of being diagnosed with mesothelioma due to their environment, work history, and/or family members. Risk factors like age, genetics, and smoking cigarettes can increase a person’s chances of developing mesotheliomas or worsen them, in some cases. These factors, however, do not directly cause mesothelioma.

About three of every four mesothelioma diagnoses are linked to asbestos exposure, and most of these are related to occupational risks from previous employment. People who are most at risk of being diagnosed with mesothelioma include occupations such as:

The attacks on September 11, 2001 in New York also put many people at risk. Thousands of residents, Manhattan workers, and first responders inhaled massive amounts of asbestos dust that had been released from the fallen buildings.


Doctors use a combination of physical exams and tests to locate and diagnose tumors. Because mesothelioma is rare among cancers, a doctor may ask about your occupation and medical history during an examination of symptoms. If your doctor believes you’re at risk, they may order a round of diagnostic tests.

Malignant mesothelioma doesn’t have a recommended screening test for those without symptoms or are at a high risk of the disease. If you were exposed to asbestos on the job, doctors recommend regular imaging tests (such as x-rays), though they may not be entirely effective in catching mesothelioma early. CT scans, PET scans, MRIs, and echocardiograms may be used to determine whether suspicious lumps or swelling are linked to cancerous tumors. While imaging scans can indicate the presence of cancer, biopsies are needed to make specific diagnoses of cancer cell types.

Currently, a biopsy test is the only way to diagnose mesothelioma. A biopsy uses a needle to remove a sample of cells to analyze beneath a microscope.


The stage of cancer describes its location since tumors first started developing, how large the tumors are, and whether or not they have spread to other areas of the body. Cancers are typically staged from I (1) to IV (4), with lower numbers representing earlier-stage cancers. Unfortunately, most mesothelioma patients are diagnosed in the advanced stages of the disease.

The stages for mesotheliomas in the chest (i.e., tumors in the pleural lining) are different than the staging of mesotheliomas in the abdomen (tumors in the peritoneum), and mesotheliomas in the heart (tumors in the pericardium).

Stage of Mesothelioma


Stage I Cancerous cells can be found in the pleura surrounding one lung on one side of the body.
Stage Ia Cancerous cells can be found in the outer layer of the pleura (i.e., parietal pleura) surrounding one lung on one side of the body.
Stage Ib Cancerous cells can be found in the innermost layer of the pleura (i.e. visceral pleura) surrounding one lung on one side of the body.
Stage II Cancerous cells can be found on both layers of the pleura, but only on one lung. Masses of cells have increased to the size of notable tumors and may have started to spread to nearby diaphragm muscles or lung tissues.
Stage III Tumors have spread to the chest wall, nearby lymph nodes, or the pericardium (i.e., the layer of tissue surrounding the heart), but may be small enough to remove via surgery.
Stage IV Tumors are larger and have spread throughout different parts of the body (the chest wall, diaphragm, peritoneum, the other lung, other organs in the chest, lymph nodes, above the collarbone, etc.). Surgery is no longer an option for treatment.

Other types of mesothelioma (including peritoneal and pericardial) are too rare even among mesotheliomas to have an established staging system. Regardless, many doctors may still refer to the above staging system when talking about the spread of mesothelioma tumors.


Overall, the mesothelioma prognosis for all types of this cancer is poor. Most people with mesothelioma only learn of their illness after it has metastasized to other organs, lymph nodes, and/or bones. Mesothelioma treatment options at this stage are few and there are no options for a cure.

Cancer survival timelines are most often measured by five-year survival rates. The rate is an average of all surviving patients five years after being diagnosed with mesothelioma. The five-year survival rate for pleural mesothelioma that has begun to spread is 12 percent.

Patients diagnosed with malignant pleural mesothelioma between 2009 and 2015 average the following five-year survival rates today:

  • Localized mesothelioma: 20 percent
  • Regional mesothelioma: 12 percent
  • Distant: 8 percent
  • All stages of mesothelioma combined: 10 percent

Types of Mesothelioma

Mesothelioma is a rare type of cancer that begins in mesothelial cells in different parts of the body. Mesothelial cells can be found in the lining of the chest, heart, and abdominal cavities. These cells are also located in the mesothelium of the testicles.

Pleural Mesothelioma

Pleural mesothelioma begins in the tissue that surrounds the lungs. It is the most common type of mesothelioma, accounting for up to 80 percent or approximately 2,500 to 3,000 cases each year.

Pleural mesothelioma symptoms typically begin with persistent chest pain or cough. You may feel short of breath easily, are often fatigued, or lose weight without trying. If you feel lumps beneath the skin on your chest, you may have late-stage mesothelioma.

Peritoneal Mesothelioma

Peritoneal metastases refer to cancer that has spread to the peritoneum, such as peritoneal mesothelioma. This type of mesothelioma begins in the tissues surrounding the organs in the abdominal cavity. It is the second-most common type of mesothelioma, making up between 15 and 20 percent of diagnoses yearly.

Symptoms often include swelling in the belly and stomach pain caused by growing tumors. Lumps in the abdomen and unexplained weight loss are symptoms of advanced cancer.

Pericardial Mesothelioma

Pericardial mesothelioma occurs in the tissue sac covering the heart known as the pericardium. Only one percent of mesothelioma cases begin in the pericardium.

Symptoms include frequent chest pain, shortness of breath, a persistent cough, and/or heart palpitations.

Testicular Mesothelioma

Testicular mesothelioma is an exceedingly rare type of cancer with only a few hundred cases ever diagnosed in the U.S.

Symptoms of testicular mesotheliomas are hard to determine due to the cancer’s rarity. The most common symptoms among patients diagnosed with the testicular form are lumps on the scrotum that don’t cause any pain.

Cell Types

When making a diagnosis, doctors looking at a sample of the types of cells from the affected area. The three main types of mesothelioma cells include:

Cell Type Shape Description
Epithelioid square The most common cell type as well as the easiest to identify. This type is usually easier to remove via surgery, giving patients better prognoses.
Fibrous sarcomatoid oval Sarcomatoid cells account for about 15 to 20 percent of cases. This type is often more aggressive and spreads faster, resulting in poorer prognoses.
Biphasic Mix of cell types A mixture of epithelioid and sarcomatoid cells making up between 20 and 30 percent of cases. This type is harder to treat than epithelioid.

Mesothelioma Treatment Options

Mesothelioma is a difficult disease to treat, even when caught in its early stages because tumors grow in multiples and spread quickly to nearby tissues. The stage of cancer is typically the main factor in determining the course of treatment, followed by the patient’s overall health and ability to recover from treatment.

Stage I and II mesotheliomas may be treated with surgery followed (or precipitated) by a round of chemotherapy or radiation. Advanced-stage mesotheliomas that have spread to other parts of the body may be treated with emerging treatments like targeted therapy and immunotherapy. For all cancer patients, doctors often prescribe some form of palliative treatment.

Deciding on a treatment plan that prioritizes your overall wellbeing while achieving treatment goals is important. You may need to seek a second opinion or travel to other cities for more mesothelioma treatment options.

Finding Treatment

Because mesothelioma is a rare type of cancer, many doctors and oncologists have not yet diagnosed or treated someone with mesothelioma. Additionally, many hospitals across the country aren’t able to offer a wide range of treatments (such as CAR T-cell therapy).

You may need to travel to another city or state to meet with a mesothelioma doctor. You may consider entering a clinical trial to receive new treatments still being studied.

Request a free mesothelioma guide for help finding professional and experienced treatment.

What to Do After Being Diagnosed With Mesothelioma

After being diagnosed with mesothelioma, you may feel overwhelmed. With all of the new information about prognosis, treatments, and recovery, it can be difficult to make decisions. But, there are several options to help you financially as well as legally.

Financial and Legal Options

Many people who have been diagnosed with mesothelioma did not develop the disease naturally. If you’ve been diagnosed, it’s possible you were exposed to asbestos while at work or in your home. Workers’ compensation laws protect people who fall ill from exposure while working. Other regulations and trust funds are available to protect senior citizens who have retired.

Bringing legal action against a company (or companies) responsible may result in financial compensation to cover the costs of treatment or in cases of wrongful death. Mesothelioma patients and their families should consider the following legal options:

Finding Support and Mesothelioma Resources

The mental health effects of a cancer diagnosis can be severe for patients as well as their families. Seeking support groups and resources may benefit those who need help coping with grief, handling legal challenges, and/or keeping up with a household.

The American Cancer Society maintains a database of support resources including mesothelioma support groups, patient lodging programs, cancer treatment information call centers, rides to treatment, and more. Many of these programs and services are free or low-cost to patients and their loved ones.

Frequently Asked Questions

  • What tests will I need to diagnose mesothelioma? Imaging tests may tell a doctor that cancers are present, but a biopsy is required to make a diagnosis.
  • What complications does mesothelioma cause? The most common side effects of mesothelioma are respiratory complications (like shortness of breath) and swelling in the chest or abdomen.
  • How do I know if my cancer is serious? Your doctor will inform you of your stage of cancer and how far it has spread. Typically, stage III and IV mesotheliomas are considered advanced-stage cancer and are harder to treat.
  • Will I need to have radiation or chemotherapy? Your treatment plan may include multiple rounds of radiation or chemotherapy, depending on your stage of cancer, your overall health, and how likely you are to recover from treatment.
  • How do I find a clinical trial for mesothelioma? Visit the National Cancer Institute’s Treatment Clinical Trials for Mesothelioma page for ongoing clinical trials accepting new patients and studies that have already concluded. You can also ask your doctor about current clinical trials in your area.
  • Should I take special vitamins or follow a new diet to help my cancer? Complementary therapies like herbal supplements, acupuncture, and meditation may improve a patient’s wellbeing but should not be substituted for medical treatment.
  • Can I sue the company that exposed me to asbestos? You may be able to file a personal injury (or wrongful death lawsuit on behalf of a loved one) if you can prove the company was responsible for your illness. Speak with an experienced mesothelioma attorney to learn more about your legal options.

Mesothelioma Support Team

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