Epithelioid mesothelioma (EM) is a type of cancer that develops in the epithelial cells that line the inner and outer surfaces of the body. This type of cancer can occur following asbestos exposure.
There are two main types of EM: pleural and peritoneal. Pleural EM affects the pleura, the lining of the lungs, while peritoneal EM affects the peritoneum, the lining of the abdominal cavity.
This article focuses primarily on pleural EM, the most common of the two types.
Mesothelioma is a cancer that
According to Cancer Research UK, doctors categorize mesotheliomas according to the body part in which they develop and the types of cells they affect. There are two main types of mesothelioma, each with three sub-types.
The two main types of mesothelioma are pleural mesothelioma and peritoneal mesothelioma.
The three cell subtypes are:
- epithelioid mesothelioma (EM)
- biphasic mesothelioma
- sarcomatoid mesothelioma
EM is the most common subtype, and most cases affect the pleura.
The most common form of EM is pleural EM. Since this type develops in the membrane surrounding the lungs, the most common symptoms are chest pain and shortness of breath.
Less common symptoms of pleural EM include:
Asbestos is the
Manufacturers once used asbestos as a building material in homes and other buildings, many of which still exist. Renovation or demolition projects can disturb the asbestos, causing the microscopic fibers to become airborne.
Researchers do not know the prevalence of malignant pleural mesotheliomas (MPMs) across the world. However, estimates suggest that mortality due to this condition may be as high as 38,400 people per year.
Populations with an increased risk
Populations that
People with jobs in the following industries are among those with a higher risk of experiencing exposure at work:
- asbestos milling, mining, or removal
- construction and building
- demolition or drywall removal
- automobile work, such as brake repair
- manufacturing
- shipbuilding
- firefighting
Others with an increased risk of illnesses related to asbestos exposure include individuals who took part in the rescue and cleanup efforts at the site of the September 11th attacks on the World Trade Center, and people who lived or went to schools nearby.
Research also suggests an association between the following factors and MPM:
Learn about asbestos and lung cancer.
When diagnosing EM, doctors will ask about a person’s symptoms and any history of asbestos exposure. They may also physically examine the chest or abdomen.
According to the
- Chest X-ray: This can show possible signs of mesothelioma, such as:
- unusual thickening of the pleura
- calcium deposits on the pleura
- fluid in the space between the lungs and chest wall
- asbestos-induced changes in the lungs
- Other imaging tests: This may include:
- a CT scan of the chest or abdomen to locate the cancer and determine whether it has spread, and if so, how far
- a PET scan to learn whether the thickening of the pleura is due to cancer or scar tissue and see if cancer has spread to other body parts
- an MRI scan, which helps show the exact location and extent of tumors in soft tissues
- Blood tests: These can check for levels of certain substances, such as fibulin-3 and soluble mesothelin-related peptides, which are often higher in people with mesothelioma.
- Tissue and fluid testing: These tests help doctors detect cancer cells in different body tissues. Examples include:
- fluid samples, which involve inserting a long, thin needle into the chest, abdomen, or lining of the heart and removing a sample of fluid for microscopic analysis
- needle biopsies, which involve inserting a long, thin needle into the affected body part and removing a small sample of cells for microscopic analysis
- endoscopic biopsies, in which doctors use a tube-like instrument with a camera and tiny tools to look inside the body and collect tissue samples
- surgical biopsies, which involve making an incision in the chest or abdomen and removing part or all of a tumor
- Pulmonary function tests (PFTs): These tests assess lung function. Doctors may request a PFT to determine whether surgery is a viable treatment option for EM or to assess lung function over time.
Treatment for EM may include a combination of surgery, radiation therapy, and chemotherapy.
Surgery
The
- Extrapleural pneumonectomy (EPP): Doctors may reserve EPP for people with potentially curable cases, such as when EM has not spread to the lymph nodes. EPP involves removal of the following from the side of the body where there is cancer:
- the lung
- the pleura lining the chest wall
- the diaphragm
- the pericardium, the sac surrounding the heart
- nearby lymph nodes
- Pleurectomy/decortication (P/D): P/D involves removing parts of the pleura affected by cancer, leaving the lung and diaphragm intact. It may help cure early cancers or relieve symptoms when doctors cannot remove the tumor.
- Partial pleurectomy (debulking): Debulking aims to remove as much of the cancer as possible.
The type of surgery a doctor recommends will depend on factors such as the person’s overall health, the type of cancer, and whether the cancer has spread.
Radiation therapy
Doctors may recommend radiation therapy to destroy any remaining cancer cells they were unable to remove surgically or to ease EM symptoms as part of palliative treatment.
Chemotherapy
Doctors may recommend chemotherapy treatment before surgery to help shrink tumors.
Alternatively, they may recommend chemotherapy after surgery to help destroy any remaining cancer cells and delay or prevent the cancer from growing back.
Chemotherapy drugs that can help treat mesothelioma
- pemetrexed (Alimta)
- cisplatin (Platinol)
- carboplatin (Paraplatin)
- gemcitabine (Gemzar)
- vinorelbine (Navelbine)
Other treatment options
According to the
Immunotherapy drugs work by helping the body’s own immune system to fight cancer, while targeted therapy drugs work in different ways to help prevent the cancer cells from growing and spreading.
A
In this review, people with EM had a median survival time of 18 months from diagnosis, compared with 10 months for people with biphasic mesothelioma and 7 months for those with sarcomatoid mesothelioma.
Across all types of mesothelioma, people receiving combined surgery and chemotherapy typically had a more favorable outlook than those having single-line therapy. Additional radiation therapy did not appear to significantly affect survival outcomes.
MPM relative survival rates
The table below shows 5-year relative survival rates among people with diagnoses of different stages of MPM between
This information comes from the Surveillance, Epidemiology, and End Results (SEER) Program, an authoritative source of cancer statistics in the United States.
| SEER stage | Description | 5-year relative survival rate |
|---|---|---|
| localized | cancer is limited to the pleura | 24% |
| regional | cancer has spread to nearby lymph nodes or other structures | 16% |
| distant | cancer has spread to distant parts of the body, such as: • the pleura on the opposite side of the body • the liver • the bones | 7% |
Other factors that can affect survival include:
- the person’s overall health
- how resectable the cancer is
- how the cancer responds to treatment
Understanding relative survival rates
A relative survival rate helps give an idea of how long a person with a particular condition may live after receiving a diagnosis compared with someone without the condition.
For example, if the 5-year relative survival rate is 70%, a person with the condition may be 70% as likely to live for 5 years from the time of diagnosis as someone without the condition.
However, it is important to remember that these figures are only estimates. A person can consult a healthcare professional to learn more about how their condition may affect them.
Anyone who has worked with or come into contact with asbestos and is concerned about the possible health effects can talk with a doctor for further advice. Asbestos exposure is by far the
People should also see a doctor if they develop symptoms of EM, such as chest pain or shortness of breath, despite never having come into contact with asbestos. EM without a known cause is rare but still possible.
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Epithelioid mesothelioma (EM) is a cancer that develops in the epithelial cells that line the inner and outer surfaces of the body. Pleural EM, the most common form, affects the lining of the lungs, potentially causing chest pain and shortness of breath.
Most cases of EM occur due to asbestos exposure at work. Anyone who has come into contact with asbestos can talk with a doctor for advice about the potential effects on their health.
Treatment for EM typically includes a combination of surgery, chemotherapy, and possibly radiotherapy. Doctors can provide people with more information about their treatment options and outlook.