Not too many people have heard of the cancer malignant mesothelioma. It usually takes someone you know to be diagnosed in order to learn about it. It’s truly amazing and scary how mesothelioma cancer cells can affect all the different tissues and parts of the body.
The mesothelium is a layer of specialized cells that lines the inside of your chest, abdomen, and the area around your heart. The mesothelium also lines the outer surface of most of your internal organs, like your stomach, liver, kidneys, etc. This layer of mesothelial cells that line your organs is important for making a special lubricant that allows organs to slide against each other. When one or more cells of the mesothelium are damaged and start to grow out of control, it can cause malignant mesothelioma.
Mesothelioma Cancer Diagnosis: Who is at Risk?
Mesothelioma cancer is rare in the United States, with only approximately 3,000 cases being diagnosed a year. This type of cancer is more common in whites and Hispanics and is much more common in older people than younger people. The average age of diagnosis of malignant mesothelioma is 72.
There are four main parts of the body where mesothelioma is typically diagnosed: pleural mesothelioma (lining of the lungs), peritoneal mesothelioma (lining in the abdomen), pericardial mesothelioma (lining around the heart), and mesothelioma of the tunica vaginalis (lining of the testicles).
The main cause of mesothelioma is asbestos exposure. In particular, pleural mesothelioma has been linked to high levels of asbestos exposure, usually in the workplace. Asbestos consists of long and thin fibrous crystals composed of six naturally occurring silicate minerals. It can be found in soil and rocks in many parts of the world. Until we connected asbestos to cancer, asbestos was used in many products because it is known to be heat and fire-resistant. It was used as an electrical insulator in many buildings and homes. The United States stopped using asbestos many decades ago, but it’s most likely still in some products and in some buildings constructed a long time ago. Most people are exposed to very low levels of naturally occurring asbestos by simply being outside and breathing in dust that comes from rocks and soil, which is usually harmless. If there’s a high amount of asbestos in a particular area, it can also be found in the water supply, which can be more dangerous. Peritoneal mesothelioma can also occur from asbestos exposure if someone breathes in asbestos and then coughs and swallows.
Is Mesothelioma Genetic?
In recent years a gene called BAP1 was discovered that is also known to cause malignant mesothelioma, among other cancers. Although rare compared to asbestos exposure, a mutation in the BAP1 gene could explain a diagnosis of mesothelioma and risk to other family members, especially if there was no exposure to asbestos. BAP1 tumor predisposition syndrome is an inherited disorder that causes both malignant and benign tumors in the skin, eyes, kidneys, and mesothelium. Skin cancers associated with BAP1 mutations include melanoma and basal cell carcinoma. In addition, an eye cancer called uveal melanoma can be associated with this mutation. The most common type of malignant mesothelioma associated with BAP1 mutations is peritoneal mesothelioma. When an individual has a BAP1 mutation, they are at risk of developing any of these cancers at a younger age, and these cancers tend to be more aggressive.
If a BAP1 mutation is found in your family, each family member has a 50% chance of inheriting the mutation. The mutation is passed down in families in an autosomal dominant pattern, meaning cancer is typically seen in every generation of a family. There is genetic testing available for the BAP1 gene to determine if a mutation explains the cancer in a family. It is recommended to test a member of the family diagnosed with a cancer that can be associated with the BAP1 mutation.
Let’s Fight Mesothelioma Cancer Together
If you or a family member have a diagnosis of mesothelioma, or have a family history of any cancer associated with BAP1 mutation, or simply want to understand your risk of cancer, please contact AT-GC to meet with a genetic counselor.