Mesothelioma is a cancer that starts as a growth of cells in the mesothelium. The mesothelium is a thin layer of tissue that covers many internal organs.

Mesothelioma is pronounced me-zoe-thee-lee-O-muh. It most often happens in the tissue around the lungs. This is called pleural mesothelioma. Mesothelioma also can happen in the tissues in the belly, around the heart and around the testicles.

Mesothelioma, which is sometimes called malignant mesothelioma, is a fast-growing and deadly form of cancer. There are mesothelioma treatments. But for many people with mesothelioma, there is no cure.

Symptoms

Signs and symptoms of mesothelioma depend on where the cancer starts.

Pleural mesothelioma affects the tissue around the lungs. Symptoms may include:

• Chest pain.
• Painful coughing.
• Shortness of breath.
• Lumps under the skin on the chest.
• Tiredness.
• Weight loss without trying.

Peritoneal mesothelioma affects tissue in the belly. Symptoms may include:

• Belly pain.
• Belly swelling.
• Nausea.
• Tiredness.
• Weight loss without trying.

Other types of mesothelioma are very rare. Not as much is known about these other types.

Pericardial mesothelioma affects tissue around the heart. It may cause trouble breathing and chest pains.

Mesothelioma of tunica vaginalis affects tissue around the testicles. It may first appear as swelling or a mass on a testicle.

When to see a doctor

Make an appointment with a doctor or other healthcare professional if you have any symptoms that worry you.

Causes

It's not always clear what causes mesothelioma. Experts believe that being around asbestos causes many mesotheliomas. But not everyone with mesothelioma has been around asbestos. Exactly what causes the cancer may not be known.

Mesothelioma is a cancer that starts as a growth of cells in the mesothelium. The mesothelium is a thin layer of tissue that covers many internal organs.

Mesothelioma happens when cells in the mesothelium develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time.

In cancer cells, the DNA changes give other instructions. The DNA changes tell the cancer cells to make more cells quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells.

The cancer cells might form a mass called a tumor. The tumor can grow to invade and destroy healthy body tissue. In time, cancer cells can break away and spread to other parts of the body. When cancer spreads, it's called metastatic cancer.

Risk factors

Being around asbestos is the biggest risk factor for mesothelioma. Asbestos is a natural mineral. Asbestos fibers are strong, and they resist heat. This makes them useful in many ways. Asbestos gets used in insulation, brakes, shingles, flooring and many other products.

Mining asbestos or removing asbestos insulation breaks up the mineral. This may create dust. If people breathe in or swallow the dust, the asbestos fibers settle in the lungs or in the stomach. This may lead to mesothelioma.

Experts don't know the exact way asbestos causes mesothelioma. It can take 15 to 40 years or more to get mesothelioma after being exposed to asbestos.

Most people who have been around asbestos don't get mesothelioma. So other factors may be involved. For instance, it could run in families, or some other condition could raise the risk.

Factors that may raise the risk of mesothelioma include:

• Being around asbestos. If you've been directly exposed to asbestos fibers at work or at home, your risk of mesothelioma is increased.
• Living with someone who works with asbestos. People who work with asbestos may carry the fibers home on their skin and clothing. Over many years, these fibers can put others in the home at risk of mesothelioma.
• A family history of mesothelioma. If your parent, sibling or child has mesothelioma, you may have a higher risk of this disease.
• Radiation therapy to the chest. If you had radiation therapy to your chest for cancer, you might have a higher risk of mesothelioma.

Complications

As pleural mesothelioma spreads in the chest, it puts pressure on the structures in that area. This can cause complications such as:

• Trouble breathing.
• Chest pain.
• Trouble swallowing.
• Pain caused by pressure on the nerves and spinal cord.
• Buildup of fluid in the chest, called pleural effusion. The fluid can press on the nearby lung and make breathing hard.

Prevention

Reducing your exposure to asbestos may lower your risk of mesothelioma.

Find out whether you work with asbestos

Most people with mesothelioma were around the asbestos fibers at work. Workers who may be around asbestos fibers include:

• Asbestos miners.
• Electricians.
• Plumbers.
• Pipefitters.
• Insulators.
• Shipyard workers.
• Demolition workers.
• Brake mechanics.
• Selected military personnel.
• Home remodelers.

Ask your employer whether you have a risk of asbestos exposure on the job.

Preparing for an appointment

Follow your employer's safety rules

Follow all safety rules in your workplace. Wear protective gear. You also may need to change out of your work clothes and wash with soap and water before eating or going home. Talk to your healthcare professional about other ways you can protect yourself from asbestos.

Prevention

Be safe around asbestos in your home

Older homes and buildings may have asbestos. In many cases, it's better to leave the asbestos in place rather than trying to remove it. Breaking up asbestos may release fibers in the air. Then you could inhale them.

Talk with experts trained to find asbestos in the home. These experts may test the air in your home to see whether the asbestos is a risk to your health. Don't try to remove asbestos from your home. Hire an expert.

Diagnosis

Mesothelioma diagnosis may start with a physical exam. A healthcare professional may check for lumps or other signs.

You might have imaging tests to look for mesothelioma. These could include a chest X-ray and a CT scan of your chest or belly.

Based on the results, you may have more tests to see whether mesothelioma or another disease is causing your symptoms.

Biopsy

A biopsy is a procedure to remove a sample of tissue for testing in a lab. Biopsy is the only way to confirm or rule out mesothelioma. The type of biopsy depends on what area of your body the mesothelioma affects.

Biopsy procedures include:

• Putting a needle through the skin. A healthcare professional might remove fluid or a piece of tissue with a thin needle put through the skin of the chest or belly.
• Taking a sample of tissue during surgery. A surgeon might take fluid or a tissue sample during surgery. The surgeon might make a small cut and insert a tube with a video camera to see inside your chest or belly. The surgeon can pass tools through the tube to get a tissue sample.

The tissue sample goes to a lab for tests. The results can show whether the tissue is mesothelioma.

Finding the extent of the cancer

Once your healthcare professional confirms mesothelioma, you may have other tests to find whether your cancer has spread to your lymph nodes or to other areas of your body.

Tests may include:

• CT scans of the chest and belly.
• MRI.
• Positron emission tomography scan, also called PET scan.

Your healthcare professional uses the results of these tests to give your cancer a stage. The stage helps your healthcare professional choose the treatments that are right for you.

Mesothelioma stages

The stages of pleural mesothelioma go from 1 to 4. A lower number means the cancer is more likely to be just in the area around the lungs. As the cancer grows larger and spreads to the nearby lymph nodes, the numbers get higher. A stage 4 mesothelioma has spread to other areas of the body.

Other types of mesothelioma don't have formal stages.

Treatment

Your treatment for mesothelioma depends on your health and certain aspects of your cancer, such as its stage and where it is.

Mesothelioma often spreads quickly. For most people, there is no cure. Healthcare professionals most often diagnose mesothelioma past the point where surgery can remove it. Instead, your healthcare team may work to manage your cancer to increase your comfort.

Talk about your treatment goals with your healthcare team. Some people want to do everything they can to treat their cancer. That means putting up with the side effects of treatment for a small chance of getting better. Others want treatments that help them live the time they have left with as few symptoms as possible.

Surgery

Surgeons work to remove mesothelioma when it's diagnosed at an early stage. Sometimes this may cure the cancer.

Most of the time, surgeons can't remove all the cancer. Then surgery may help to reduce symptoms caused by mesothelioma spreading in the body.

Surgery types may include:

• Surgery to reduce fluid buildup. Pleural mesothelioma may cause fluid to build up in the chest. This can make it hard to breathe. Surgeons put a tube into the chest to drain the fluid.

  Healthcare professionals also may put medicine into the chest to keep fluid from coming back. This is called pleurodesis.

• Surgery to remove the tissue around the lungs. Surgeons may remove the tissue lining the ribs and the lungs. This is called pleurectomy. This procedure won't cure mesothelioma. But it may ease symptoms.
• Surgery to remove a lung and the tissue around it. Removing the affected lung and the tissue around it may ease symptoms of pleural mesothelioma. If you have radiation therapy to the chest after surgery, this procedure also allows higher doses of radiation. That's because there's no need to protect the lung from radiation.
• Surgery for peritoneal mesothelioma. Surgery for peritoneal mesothelioma might remove as much of the cancer as possible. You might have chemotherapy before or after surgery.

Chemotherapy

Chemotherapy treats cancer with strong medicines. Healthcare professionals might use chemotherapy before surgery. It also can help treat mesothelioma that grows large or spreads to other parts of the body.

Chemotherapy medicines also may be heated and put into the belly cavity. This is called hyperthermic intraperitoneal chemotherapy, also known as HIPEC. HIPEC can help treat peritoneal mesothelioma.

Radiation therapy

Radiation therapy treats cancer with powerful energy beams. The energy can come from X-rays, protons or other sources.

Radiation can kill cancer cells that are left after surgery. It also may be given before surgery to shrink the cancer. And it may help ease symptoms of cancer that surgery can't treat.

Immunotherapy

Immunotherapy for cancer is a treatment with medicine that helps the body's immune system kill cancer cells. The immune system fights off diseases by attacking germs and other cells that shouldn't be in the body. Cancer cells survive by hiding from the immune system.

For mesothelioma, immunotherapy might be used after surgery or when surgery isn't an option.

Targeted therapy

Targeted therapy for cancer is a treatment that uses medicines that attack specific chemicals in the cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die.

For mesothelioma, targeted therapies may be combined with chemotherapy. Targeted therapies may be used if other treatments haven't helped.

Clinical trials

Clinical trials are studies of new treatment methods. People with mesothelioma may choose a clinical trial for a chance to try new types of treatment. But a cure isn't guaranteed. Think about your treatment options and talk with your healthcare professional about clinical trials that are open to you. Being in a clinical trial may help experts better learn how to treat mesothelioma in the future.

Treatment for other types of mesothelioma

Pericardial mesothelioma and mesothelioma of tunica vaginalis are very rare. Surgeons may remove small cancers that haven't spread away from where they started. But healthcare professionals have yet to find the best way to treat cancers that have spread. Your healthcare team may suggest certain treatments to improve your quality of life.

Alternative medicine

No alternative medicine treatments have proved helpful in treating mesothelioma. But complementary and alternative treatments may help manage mesothelioma symptoms. Talk with your healthcare team if you want to try these treatments.

Mesothelioma can cause pressure within your chest that can make you feel as if you're always short of breath. Your healthcare team may suggest using supplemental oxygen or taking medicines to make you more comfortable. But often these aren't enough.

Using the treatments your healthcare team suggests with complementary and alternative approaches may help you feel better.

Alternative treatments that have shown some promise in helping people cope with trouble breathing include:

Acupuncture

Acupuncture uses thin needles put into your skin at precise points.

Breath training

A nurse or physical therapist can teach you ways to breathe to use when you feel breathless. Sometimes you may feel breathless and begin to panic. Using these ways to breathe may help you feel like you're managing your breathing better.

Relaxation exercises

Slowly tensing and relaxing muscle groups may help you feel more at ease and breathe better. Your healthcare team may send you to a therapist who can teach you relaxation exercises so that you can do them on your own.

Sitting near a fan

Putting a fan toward your face may help ease feeling breathless.

Coping and support

A diagnosis of mesothelioma can be devastating not only to you but also to your family and friends. To regain a sense of control, try to:

Learn enough about mesothelioma to make decisions about your care

Write down questions to ask your healthcare professional. Ask your healthcare team for information to help you better understand your disease. Good places to start looking for more information include the U.S. National Cancer Institute, the American Cancer Society and the Mesothelioma Applied Research Foundation.

Surround yourself with a support network

Close friends or family can help you with everyday tasks, such as getting you to appointments or treatment. If you have trouble asking for help, learn to be honest with yourself and accept help when you need it.

Seek out other people with cancer

Ask your healthcare team about cancer support groups in your community and online. Sometimes there are questions that can only be answered by other people with cancer. Support groups offer a chance to ask these questions and receive support from people who understand your situation.

Plan ahead

Ask your healthcare team about advance directives. Advance directives give your family guidance on your medical wishes in case you can no longer speak for yourself.

Preparing for an appointment

Start by making an appointment with a doctor or other healthcare professional if you have symptoms that worry you. Your healthcare professional may send you to a specialist. Which specialist you see may depend on your symptoms. For lung symptoms, you may see a doctor who specializes in lung diseases, called a pulmonologist. For symptoms in the belly, you may see a doctor who specializes in conditions affecting the digestive system, called a gastroenterologist.

Here's some information to help you get ready for your appointment.

What you can do

• Be aware of what you need to do before your appointment. When you make the appointment, ask if, for instance, you need to restrict your diet before a test.
• Write down your symptoms and when they began. Include any that don't seem linked to the reason for which you made the appointment.
• Write down key personal information, including any major stresses or recent life changes.
• Make a list of all medicines, vitamins or supplements you take or have taken recently. Include the dosages.
• Think about taking a family member or friend along. Someone who goes with you to the appointment may remember something that you missed or forgot.
• Bring medical records that relate to your condition. This might include past chest X-rays.
• Write down questions to ask your healthcare professional.

For mesothelioma, some basic questions to ask include:

• What is likely causing my symptoms or condition?
• What are other possible causes for my symptoms or condition?
• What tests do I need?
• Is my condition likely to go away or to last?
• What is the best course of action?
• I have other health conditions. How can I best manage them together?
• Are there brochures or other printed material that I can have? What websites do you suggest?

Be sure to ask all the questions you have.

What to expect from your doctor

Your healthcare professional may ask you questions, such as:

• Do you always have your symptoms or do they come and go?
• How bad are your symptoms?
• What, if anything, seems to make your symptoms better?
• What, if anything, seems to make your symptoms worse?
• Does it hurt to take a deep breath?
• Do your symptoms keep you from working or doing daily activities?
• Have you ever worked with asbestos?

What you can do in the meantime

Try not to do anything that makes your symptoms worse. For instance, if you're short of breath, try to take it easy until you can meet with your healthcare professional. If you feel too breathless, seek medical attention right away.