Mesothelioma is an aggressive cancer of the mesothelial cells. These cells exist in the lining that covers the outer surface of the body’s organs.
Mesothelioma occurs most often in the pleura, or the lining of the lungs. However, the cancer can also attack the linings of the heart and abdomen. The main cause is exposure to asbestos.
There is no cure, but palliative therapy may improve a patient’s quality of life.
In 2015, the fatlity rate for mesothelioma in the United States (U.S.) was 10.93 per million people. Only 9 percent of those diagnosed with mesothelioma live longer than 5 years.
Fast facts on mesothelioma:
Here are some key points about mesothelioma. More detail is in the main article.
Mesothelioma is an aggressive form of cancer that most commonly affects the lungs.
It is most likely to result from exposure to asbestos, which may have been up to 30 years before symptoms appear.
There is no cure, and treatment focuses on relieving symptoms and improving quality of life.
What is mesothelioma?
Exposure to asbestos is the main cause of mesothelioma. Symptoms may take 30 years to appear.
Cancers happen when there is uncontrolled division of mutated cells. Mesothelioma is an aggressive form of cancer, meaning that it progresses and spreads quickly.
There are three types:
Pleural mesothelioma is the most common form. It affects the pleura, or the lining around the lungs.
Peritoneal mesothelioma is the second most common form. It attacks the lining of the abdomen, called the peritoneum.
Pericardial mesothelioma is the rarest form. It affects the protective layer of the heart.
Fifty-five percent of those with mesothelioma survive for 6 months after diagnosis, and 33 percent survive for a year.
It can take up to 30 years for symptoms to show after exposure to asbestos particles and dust. Diagnosis often happens when the disease is already advanced. The outcome depends on how early the malignancy can be diagnosed.
Signs and symptoms vary depending on the location of the cancer in the body.
Pleural mesothelioma can be indicated by:
shortness of breath
coughing, often painful
unexpected and unexplained weight loss
pain under the ribcage
detectable lumps under the skin in the chest area
lower back pain
discomfort in the side of the chest
Peritoneal mesothelioma can involve:
unexplained weight loss
swelling in the abdomen
lumps in the abdomen
nausea and vomiting
Pericardial mesothelioma causes:
low blood pressure
shortness of breath
fluid retention, or edema, often in the legs
extreme fatigue following light exertion
Mesothelioma is directly linked to exposure to a combination of six minerals made from long, thin fibers called asbestos.
Asbestos is a group of minerals that occur naturally. They exist as fibers or bundles. These fibers may be found in soil or rocks and exist in many parts of the world naturally. Asbestos is made of silicon, oxygen and some other elements.
Asbestos is used in a range of products, especially building materials, including siding, floor tiles, ceiling materials, and roof shingles. Its presence is also found in friction products, such as brake parts, as well as heat-resistant fabrics, packaging, coatings, and gaskets.
It was often used in the past to insulate products and buildings and make them soundproof or fireproof.
When asbestos products are installed, repaired, or demolished, the fibers can become airborne. They can then be inhaled or swallowed and become permanently lodged in the lungs, for decades in some cases. Other organs can also be affected.
Mesothelioma can develop from these fibers.
Who is at risk?
The likelihood of developing mesothelioma is directly proportional to the length of exposure to asbestos, and how much a person inhaled. People in jobs with high exposure, such as on construction sites, steel mills, or power plants, have the highest risk of developing the disease.
Even family members who have never entered an asbestos-rich environment can be exposed. Workers exposed to asbestos can accidentally carry fibers home in their clothing, and become inhaled by other members of the household.
The World Health Organization (WHO) said that approximately 125 million people globally were exposed to asbestos at work in 2005, despite their employers having known about the link to cancer and other lung diseases for over six decades. Most work-related exposure today occurs in developing nations.
In much rarer cases, mesothelioma may be linked to:
inhalation of fibrous silicates such as erionite, zeolite and intrapleural thorium dioxide