What is pleural mesothelioma (malignant pleural mesothelioma)?
Pleural mesothelioma — or malignant pleural mesothelioma — is a rare cancer that grows in the membrane (pleura) that lines the walls of your chest and lungs. The condition gets its name from the mesothelium, a lining that protects your internal organs. Cancer that forms in any part of the mesothelium is called mesothelioma.
Prior asbestos exposure is the most common cause of pleural mesothelioma. Asbestos is a group of minerals once used in many industries, like building and manufacturing. Until the 1960s and 1970s, workers mined asbestos in the United States. Around this time, scientists discovered the link between exposure to airborne asbestos particles and mesothelioma.
Since then, government agencies and manufacturers in the U.S. have taken steps to reduce asbestos exposure to prevent people from developing mesothelioma.
What are the types of pleural mesothelioma?
In 2015, the World Health Organization (WHO) classified mesothelioma into three categories based on the types of cells in the mesothelium (mesothelial cells) where the cancer develops. Some cells lead to more aggressive (fast-growing) cancer than others.
- Epithelioid mesothelioma: The most common form of malignant mesothelioma (60% to 80% of cases). It’s the easiest type to treat.
- Sarcomatoid mesothelioma: The rarest form of malignant mesothelioma (10% of cases). It grows faster and is harder to treat than epithelioid mesothelioma.
- Biphasic mesothelioma: A rare form of malignant mesothelioma (10% to 15%). It contains a mix of epithelioid and sarcomatoid cell types.
The type of pleural mesothelioma you have will help your healthcare provider determine what treatments may work best and what your prognosis, or likely outcome, might be.
How common is pleural mesothelioma?
Mesothelioma is rare. Still, pleural mesothelioma is the most common type of mesothelioma. Approximately 3,300 people in the United States receive a mesothelioma diagnosis each year. Pleural mesothelioma accounts for about 80% of these diagnoses.
Widespread efforts to reduce asbestos exposure have led to a decline in cases in the U.S. since 2000.
Symptoms and Causes
What are the symptoms of pleural mesothelioma?
The symptoms of pleural mesothelioma set on slowly. It can take up to 50 years for pleural mesothelioma to develop after asbestos exposure. Early signs of pleural mesothelioma can be bothersome, but easy to dismiss. Many people delay seeing their healthcare provider until their cancer’s more advanced.
The main symptoms of pleural mesothelioma are ongoing chest pain and shortness of breath.
Other symptoms include:
- Persistent cough and hoarseness.
- Difficulty swallowing (dysphagia).
- Lower back pain.
- Swollen face and arms.
- Unexplained weight loss.
- Night sweats.
What causes pleural mesothelioma?
Asbestos exposure causes pleural mesothelioma in 70% of cases. And these are only the cases researchers know of for sure. The number may be higher. Asbestos consists of fibers that become tiny, airborne particles when disturbed. The particles settle in your lungs if you inhale them. They’re too tough for your body to break down. Over time, these particles can cause scarring and inflammation in your lungs. They also cause cell changes that lead to cancer.
Intact materials containing asbestos are safe. Asbestos only poses a health risk when disturbing the material releases asbestos particles into the air.
Scientists are researching potential causes of mesothelioma unrelated to asbestos exposure. Other causes may include:
- Previous radiation therapy directed at your chest.
- Genetic mutations that run in families (missing BAP1 gene).
- Exposure to carbon nanotubes, a building material that’s used to reinforce other structures (currently found in vehicles, sports equipment and many other materials).
More research is needed to understand how pleural mesothelioma develops when asbestos isn’t the clear cause.
Who is at risk for pleural mesothelioma?
Most people diagnosed with pleural mesothelioma have spent years working jobs that exposed them to large amounts of asbestos. Men and people assigned male at birth (AMAB) often work in these positions. Mesothelioma takes several years (15 to 50 years) to develop. Many people receiving diagnoses are retired (aged 65 and up) but worked around asbestos for years before it was regulated.
Professions most at risk for asbestos exposure include:
- Construction workers and builders, including shipbuilding.
- Navy service members who worked in shipyards.
- Building renovators and demolition crews.
- Automotive, factory and railway workers.
- Insulation manufacturers and installers.
You’re also at risk of asbestos exposure if you:
- Live with someone who works around asbestos and brings the particles home on their clothes.
- Live near an asbestos mine or a demolition site with buildings containing asbestos.
What are the complications of pleural mesothelioma?
Up to 95% of people with pleural mesothelioma also experience pleural effusion. This condition occurs when fluid builds up between your lungs and chest wall. Pleural effusion can make it harder to breathe.
You may also have signs and symptoms associated with other conditions that often (but not always) occur alongside pleural mesothelioma, including:
- Pleural plaques: Areas of thickened tissue on your pleura. The plaques aren’t cancerous and don’t cause symptoms, but they usually appear on imaging.
- Asbestosis: Benign lung disease that you get by inhaling asbestos. It causes scar tissue to form in your lungs, making breathing harder.
Your healthcare provider can recommend treatments to relieve symptoms like difficulty breathing or pressure on your chest.
Diagnosis and Tests
How is pleural mesothelioma diagnosed?
A healthcare provider will perform a physical exam, review your medical history and assess risk factors. They may recommend:
- Imaging tests: Chest X-rays show lung changes, like pleural thickening or pleural effusion (fluid build-up). Your provider may also order an MRI, CT scan or positron emission tomography (PET) scan to see where the tumors are located and if the cancer’s spread.
- Blood tests: Your provider may test your blood for high levels of substances often linked to mesothelioma, such as fibulin-3 and soluble mesothelin-related peptides.
- Thoracentesis: Your provider may remove a fluid sample from around your lungs to check for cancer cells. Thoracentesis can also help relieve pressure in your chest from fluid build-up in your lungs.
- Biopsy: Your provider may remove a tissue sample to test it for cancer cells. A biopsy is the only way to know if you have mesothelioma. Procedures include bronchoscopy, thoracoscopy and video-assisted thoracic (VATS) surgery.
What are the stages of pleural mesothelioma?
Cancer staging allows your provider to plan treatments and determine how advanced the disease is. They stage pleural mesothelioma from one to four, with one being least advanced and four being most advanced.
- Stage 1: Cancer is only in your pleura. At this stage, you may be a candidate for treatments like surgery to get rid of the cancer.
- Stage 2: Cancer may have spread beyond your pleura, but it’s still near the original site.
- Stage 3: Cancer has spread to nearby organs and lymph nodes.
- Stage 4: Cancer has spread to other organs, or metastasized.
Understanding your cancer stage can help your provider plan the most effective treatments for your health and well-being.
Where does pleural mesothelioma spread?
With stage four pleural mesothelioma, cancer has spread to parts of your body other than your lung. Common sites include your bones, liver, diaphragm, heart and central nervous system.
Management and Treatment
How is pleural mesothelioma managed or treated?
Pleural mesothelioma is difficult to treat because the cancer can spread along nerves, blood vessels and tissues. Often, healthcare providers who treat cancer, or oncologists, recommend a combination of treatments for pleural mesothelioma.
Treatments may include:
- Surgery: Surgery may be an option in the early stages of pleural mesothelioma. Procedures include extrapleural pneumonectomy (EPP), which removes your lung and (often) parts of your diaphragm. Pleurectomy with decortication (P/D) removes your pleura and the tumor instead of your entire lung. Surgery often accompanies other treatments, like chemotherapy or radiation.
- Radiation therapy: Radiation directs high-energy X-rays toward cancer cells, destroying them. You may receive radiation with other treatments like surgery and chemotherapy to eliminate the cancer. You may receive radiation to relieve symptoms.
- Chemotherapy: Chemotherapy uses drugs that kill cancer cells or slow their growth. Pemetrexed, carboplatin and cisplatin are common chemotherapy drugs used to treat pleural mesothelioma.
- Immunotherapy: Immunotherapy treatments strengthen your immune system so it’s better able to identify and destroy cancer cells. Depending on the type of cancer cells you have, you may receive immunotherapy to target those cancer cells.
- Palliative care: The goal of palliative care isn’t to get rid of your cancer. Instead, palliative care provides symptom relief and comfort. For example, surgery and radiation may be used to eliminate your cancer, or they can help relieve symptoms like pressure in your chest. Procedures to remove excess fluid from your lungs won’t eliminate cancer, but they’ll allow you to breathe better.
- Clinical trials: A clinical trial is a study that tests the safety and effectiveness of new treatments and treatment approaches. Several therapies show promise in clinical trials. For example, researchers are currently testing new treatment combinations for pleural mesothelioma, including various chemotherapy and immunotherapy drugs. Gene therapy and photodynamic therapy are new treatments you may be eligible for if you participate in a clinical trial.
Ask your oncologist if they’d recommend you participate in a clinical trial.
Is pleural mesothelioma curable?
There isn’t a cure for pleural mesothelioma. Still, treatments can help you live a longer life, relieve symptoms and help you stay more comfortable. Pleural mesothelioma is a serious disease, but new treatment approaches continue to improve the prognosis for people with this cancer.
How can I prevent pleural mesothelioma?
The best way to prevent pleural mesothelioma is to avoid airborne asbestos particles. Since the late 1970s, the Environmental Protection Agency (EPA) has regulated the use of asbestos in building materials. Still, many homes, buildings, cars and products made before 1980 are likely to have it. To reduce your risk:
- Have an asbestos abatement expert check your home before attempting to remodel it.
- Hire an asbestos abatement company if you plan to remove a wall or drill into a surface with asbestos.
- Wear protective gear to prevent breathing in asbestos if you work in a profession that puts you at risk. Avoid getting the particles on your clothes, hair and shoes.
Outlook / Prognosis
What is the prognosis (outlook) for people with pleural mesothelioma?
Most people with pleural mesothelioma have a life expectancy of one to four years after diagnosis. Without treatment, the life expectancy is about six months.
Still, your prognosis depends on several factors, including the type of pleural mesothelioma you have and your cancer stage. For example, epithelioid mesothelioma that’s in the early stages has a better prognosis than sarcomatoid mesothelioma in advanced stages. New therapies that can potentially prolong your life are continually under development. Ask your healthcare provider about your prognosis based on your diagnosis.
When should I call the doctor?
You should call your healthcare provider if there’s a chance you have a history of asbestos exposure and you experience:
- Back or chest pain.
- Chronic cough or hoarseness.
- Difficulty breathing or swallowing.
- Facial swelling.
- Unexplained weight loss.
What questions should I ask my doctor?
You may want to ask your healthcare provider:
- What type of pleural mesothelioma do I have?
- What stage of cancer do I have?
- What’s the best treatment for me?
- Will this treatment prolong my life? Will it improve symptoms?
- How can I manage symptoms or treatment side effects?
- Can I participate in a clinical trial?
A note from Cleveland Clinic
Pleural mesothelioma isn’t curable, but it may be treatable depending on your cancer stage and the type of cancer cells you have. Surgery, chemotherapy and (more recently) immunotherapy can potentially extend your life. These treatment options can provide symptom relief that allows you to experience your life more fully. Ask your healthcare provider about your prognosis based on your unique cancer diagnosis. Have them talk you through the pros and cons of all available treatment options so you’re making confident, informed decisions about your care plan.
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