Mesothelioma (or, more precisely, malignant mesothelioma) is a rare form of cancer that develops from transformed cells originating in the mesothelium. It affects the thin, protective membrane surrounding the lungs, heart and abdominal cavity. An estimated 3,000 cases annually are diagnosed in the United States, and the majority of those are traced to an occupational exposure.
The most common anatomical site for the development of mesothelioma is the pleura (the outer lining of the lungs and internal chest wall), but it can also arise in the peritoneum (the lining of the abdominal cavity), and the pericardium (the sac that surrounds the heart), or the tunic vaginalis (a sac that surrounds the testis).
Most people who develop mesothelioma have worked in jobs where they inhaled asbestos, or were exposed to asbestos dust and fibers in other ways. It has also been suggested that washing clothes of a family member who worked with asbestos increases their risk for developing mesothelioma. Unlike lung cancer, there seems to be no association between mesothelioma and tobacco smoking, but smoking greatly increases the risk of other asbestos-induced cancers. Some people who were exposed to asbestos have collected damages for asbestos-related disease, including mesothelioma. Compensation via asbestos funds or class action lawsuits is an important issue in law practices regarding mesothelioma.
How Asbestos Causes Mesothelioma
Mesothelioma cancer develops after exposure to asbestos, which most often occurs in the workplace –in industrial settings, shipyards, auto repair shops, old houses, schools and public buildings. It takes long-term exposure to make someone at risk, but heavy, short-term asbestos exposure has been known to cause mesothelioma cancer.
Microscopic asbestos fibers are breathed in or swallowed. The human body has difficulty destroying or getting rid of these fibers. Over decades, the fibers cause biological changes that result in inflammation, scarring and genetic damage. The most susceptible area to these fibers is the lining of the lungs, called the pleura, although fibers also can become trapped in the lining of the abdominal cavity (peritoneum). Once fibers cause biological damage, the stage is set for a 30- to 50-year latency period for mesothelioma to develop.
In general, cancer begins when a series of genetic mutations occur within a cell, causing the cell to grow and multiply out of control. It isn't clear what causes the initial genetic mutations that lead to mesothelioma, though researchers have identified factors that may increase the risk. It's likely that cancers form because of an interaction between many factors, such as inherited conditions, your environment, your health conditions and your lifestyle choices.
Mesothelioma doesn't include a noncancerous tumor
A form of noncancerous (benign) tumor that can occur in the chest is sometimes called benign mesothelioma. However, this name is misleading. Benign mesothelioma doesn't begin in the same cells where the cancerous forms of mesothelioma begin. And, in a minority of cases, benign mesothelioma can be very aggressive, despite the term "benign." For this reason, some doctors now refer to this tumor as solitary fibrous tumor.
Solitary fibrous tumor usually doesn't cause signs and symptoms. Most cases are inadvertently discovered during tests and procedures for other conditions. It isn't clear what causes solitary fibrous tumors, but they aren't linked to asbestos exposure. Treatment for solitary fibrous tumor typically includes surgery.
Symptoms
Signs and symptoms of mesothelioma vary depending on where the cancer occurs.
Pleural mesothelioma, which affects the tissue that surrounds the lungs, causes signs and symptoms that may include:
- Chest pain under the rib cage
- Painful coughing
- Shortness of breath
- Unusual lumps of tissue under the skin on your chest
- Unexplained weight loss
Peritoneal mesothelioma, which occurs in tissue in the abdomen, causes signs and symptoms that may include:
- Abdominal pain
- Abdominal swelling
- Lumps of tissue in the abdomen
- Unexplained weight loss
Other forms of mesothelioma
Signs and symptoms of other types of mesothelioma are unclear. Other forms of mesothelioma are so rare that not much information is available. Pericardial mesothelioma, which affects tissue that surrounds the heart, can cause signs and symptoms such as breathing difficulty and chest pains. Mesothelioma of tunica vaginalis, which affects tissue surrounding the testicles, may be first detected as a mass on a testicle.
Signs and symptoms of other types of mesothelioma are unclear. Other forms of mesothelioma are so rare that not much information is available. Pericardial mesothelioma, which affects tissue that surrounds the heart, can cause signs and symptoms such as breathing difficulty and chest pains. Mesothelioma of tunica vaginalis, which affects tissue surrounding the testicles, may be first detected as a mass on a testicle.
Risk factors
Asbestos exposure: The primary risk factor for mesothelioma
Asbestos is a mineral that's found naturally in the environment. Asbestos fibers are strong and resistant to heat, making them useful in a wide variety of applications, such as in insulation, brakes, shingles, flooring and many other products.
Asbestos is a mineral that's found naturally in the environment. Asbestos fibers are strong and resistant to heat, making them useful in a wide variety of applications, such as in insulation, brakes, shingles, flooring and many other products.
When asbestos is broken up, such as during the mining process or when removing asbestos insulation, dust may be created. If the dust is inhaled or swallowed, the asbestos fibers will settle in the lungs or in the stomach, where they can cause irritation that may lead to mesothelioma, though how exactly this happens isn't understood. It can take 20 to 40 years or more for mesothelioma to develop as a result of asbestos exposure.
Some people with years of asbestos exposure never develop mesothelioma. And yet, others with very brief exposure develop the disease. This indicates that other factors may be involved in determining whether someone gets mesothelioma or doesn't. For instance, you could inherit a predisposition to cancer or some other condition could increase your risk.
Possible risk factors
Factors that may increase the risk of mesothelioma include:
Factors that may increase the risk of mesothelioma include:
- Personal history of asbestos exposure. If you've been directly exposed to asbestos fibers at work or at home, your risk of mesothelioma is greatly increased.
- Living with someone who works with asbestos. People who are exposed to asbestos may carry the fibers home on their skin and clothing. These stray fibers can put others in the home at risk of mesothelioma. People who work with asbestos should shower and change clothes before leaving work.
- A monkey virus used in polio vaccines. Some research indicates a link between mesothelioma and simian virus 40 (SV40), a virus originally found in monkeys. Millions of people may have been exposed to SV40 when receiving polio vaccinations between 1955 and 1963, because the vaccine was developed using monkey cells. Once it was discovered that SV40 was linked to certain cancers, the virus was removed from the polio vaccine. Whether SV40 increases the risk of mesothelioma is a point of debate, and more research is needed.
- Radiation. Some research links mesothelioma to the radioactive substance thorium dioxide, which was used along with X-rays to diagnose various health conditions from the 1920s to the 1950s. Mesothelioma has also been linked to radiation therapy treatments to the chest, such as those used to treat breast cancer or lymphoma.
- Family history. A family history of mesothelioma may increase your risk of mesothelioma, but more research is needed to understand this theory.
TYPE OF MESOTHELIOMA
· Mesothelioma cancer or also called asbestos cancer affects the serous membranes that surround the body's internal organs including the lungs (called pleural mesothelioma), heart (called pericardium mesothelioma) and abdominal (called peritoneal mesothelioma) organs.
· Pleural Mesothelioma: The most common of mesothelioma cancer is pleural mesothelioma. The Pleural mesothelioma represents about 75% of all mesothelioma, although the most common type of cancer (malignant) mesothelioma, the disease is still somewhat of a rarity. In this case, the cancel cell affects the lungs and the protective lining and cavity of the lungs. The disease can grow quickly and enlarge the pleural space, causing it to fill with fluid. Pleural mesothelioma is caused by exposure to asbestos.
The symptoms of pleural mesothelioma result from pleural effusion, commonly the patients are having chronic chest pain. Sufferers of pleural mesothelioma may also experience some symptoms such as difficulty in breathing, difficulty in swallowing, shortness of breath, persistent coughing, weight loss, fever, coughing up of blood, and rasping.
The symptoms of pleural mesothelioma result from pleural effusion, commonly the patients are having chronic chest pain. Sufferers of pleural mesothelioma may also experience some symptoms such as difficulty in breathing, difficulty in swallowing, shortness of breath, persistent coughing, weight loss, fever, coughing up of blood, and rasping.
· Peritoneal Mesothelioma: It’s the second most common type of cancer mesothelioma; In this case the cancer cell affects the stomach and abdomen. Start in the abdominal area and spread to other parts of the body, but the tumors that press against the wall of the abdomen and then result some symptom such as abdominal pain, abdominal swelling, nausea, loss of appetite, vomiting, breathing problems, chest pain, bowel obstruction, anemia, fever, and blood clotting abnormalities.
Peritoneal mesothelioma is most often caused by the ingestion of carcinogenic asbestos fibers. When asbestos is ingested, minute fibers enter the stomach and penetrate the stomach lining.
Peritoneal mesothelioma is most often caused by the ingestion of carcinogenic asbestos fibers. When asbestos is ingested, minute fibers enter the stomach and penetrate the stomach lining.
· Pericardial Mesothelioma: The rarest form of mesothelioma is that which affects the linings of the heart cavity, called the pericardium. Patient with pericardia mesothelioma often complain of chest pain, shortness of breath, trouble breathing, persistent coughing, and palpitations.
