Information on Mesothelioma Mesothelioma Mesothelioma is an uncommon form of cancer, associated with prolonged exposure to asbestos, which affects the pleura, a sac which surrounds the lungs, the peritoneum, the lining of the abdominal cavity, or the pericardium, a sac which surrounds the heart. Mesothelioma is a rare form of cancer in which malignant (cancerous) cells are found in the mesothelium, a protective sac that covers most of the body's internal organs. Most people who develop mesothelioma have worked on jobs where they inhaled asbestos particles. Table of contents 1 What is the mesothelium? 2 What is mesothelioma? 3 How common is mesothelioma? 4 What are the risk factors for mesothelioma? 5 Who is at increased risk for developing mesothelioma? 6 What are the symptoms of mesothelioma? 7 How is mesothelioma diagnosed? 8 How is mesothelioma treated? 9 Are new treatments for mesothelioma being studied? 10 Mesothelioma Links What is the mesothelium? The mesothelium is a membrane that covers and protects most of the internal organs of the body. It is composed of two layers of cells: One layer immediately surrounds the organ; the other forms a sac around it. The mesothelium produces a lubricating fluid that is released between these layers, allowing moving organs (such as the beating heart and the expanding and contracting lungs) to glide easily against adjacent structures. The mesothelium has different names, depending on its location in the body. The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity. The pleura is the membrane that surrounds the lungs and lines the wall of the chest cavity. The pericardium covers and protects the heart. The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis. The tunica serosa uteri covers the internal reproductive organs in women. What is mesothelioma? Mesothelioma (cancer of the mesothelium) is a disease in which cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also metastasize (spread) from their original site to other parts of the body. Most cases of mesothelioma begin in the pleura or peritoneum. How common is mesothelioma? Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. About 2,000 new cases of mesothelioma are diagnosed in the United States each year. Mesothelioma occurs more often in men than in women and risk increases with age, but this disease can appear in either men or women at any age. What are the risk factors for mesothelioma? Working with asbestos is the major risk factor for mesothelioma. A history of asbestos exposure at work is reported in about 70 percent to 80 percent of all cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. Asbestos is the name of a group of minerals that occur naturally as masses of strong, flexible fibers that can be separated into thin threads and woven. Asbestos has been widely used in many industrial products, including cement, brake linings, roof shingles, flooring products, textiles, and insulation. If tiny asbestos particles float in the air, especially during the manufacturing process, they may be inhaled or swallowed, and can cause serious health problems. In addition to mesothelioma, exposure to asbestos increases the risk of lung cancer, asbestosis (a noncancerous, chronic lung ailment), and other cancers, such as those of the larynx and kidney. Smoking does not appear to increase the risk of mesothelioma. However, the combination of smoking and asbestos exposure significantly increases a person's risk of developing cancer of the air passageways in the lung. Who is at increased risk for developing mesothelioma? Asbestos has been mined and used commercially since the late 1800s. Its use greatly increased during World War II. Since the early 1940s, millions of American workers have been exposed to asbestos dust. Initially, the risks associated with asbestos exposure were not known. However, an increased risk of developing mesothelioma was later found among shipyard workers, people who work in asbestos mines and mills, producers of asbestos products, workers in the heating and construction industries, and other tradespeople. Today, the U.S. Occupational Safety and Health Administration (OSHA) sets limits for acceptable levels of asbestos exposure in the workplace. People who work with asbestos wear personal protective equipment to lower their risk of exposure. The risk of asbestos-related disease increases with heavier exposure to asbestos and longer exposure time. However, some individuals with only brief exposures have developed mesothelioma. On the other hand, not all workers who are heavily exposed develop asbestos-related diseases. There is some evidence that family members and others living with asbestos workers have an increased risk of developing mesothelioma, and possibly other asbestos-related diseases. This risk may be the result of exposure to asbestos dust brought home on the clothing and hair of asbestos workers. To reduce the chance of exposing family members to asbestos fibers, asbestos workers are usually required to shower and change their clothing before leaving the workplace. What are the symptoms of mesothelioma? Symptoms of mesothelioma may not appear until 30 to 50 years after exposure to asbestos. Shortness of breath and pain in the chest due to an accumulation of fluid in the pleura are often symptoms of pleural mesothelioma. Symptoms of peritoneal mesothelioma include weight loss and abdominal pain and swelling due to a buildup of fluid in the abdomen. Other symptoms of peritoneal mesothelioma may include bowel obstruction, blood clotting abnormalities, anemia, and fever. If the cancer has spread beyond the mesothelium to other parts of the body, symptoms may include pain, trouble swallowing, or swelling of the neck or face. These symptoms may be caused by mesothelioma or by other, less serious conditions. It is important to see a doctor about any of these symptoms. Only a doctor can make a diagnosis. How is mesothelioma diagnosed? Diagnosing mesothelioma is often difficult, because the symptoms are similar to those of a number of other conditions. Diagnosis begins with a review of the patient's medical history, including any history of asbestos exposure. A complete physical examination may be performed, including x-rays of the chest or abdomen and lung function tests. A CT (or CAT) scan or an MRI may also be useful. A CT scan is a series of detailed pictures of areas inside the body created by a computer linked to an x-ray machine. In an MRI, a powerful magnet linked to a computer is used to make detailed pictures of areas inside the body. These pictures are viewed on a monitor and can also be printed. A biopsy is needed to confirm a diagnosis of mesothelioma. In a biopsy, a surgeon or a medical oncologist (a doctor who specializes in diagnosing and treating cancer) removes a sample of tissue for examination under a microscope by a pathologist. A biopsy may be done in different ways, depending on where the abnormal area is located. If the cancer is in the chest, the doctor may perform a thoracoscopy. In this procedure, the doctor makes a small cut through the chest wall and puts a thin, lighted tube called a thoracoscope into the chest between two ribs. Thoracoscopy allows the doctor to look inside the chest and obtain tissue samples. If the cancer is in the abdomen, the doctor may perform a peritoneoscopy. To obtain tissue for examination, the doctor makes a small opening in the abdomen and inserts a special instrument called a peritoneoscope into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary. If the diagnosis is mesothelioma, the doctor will want to learn the stage (or extent) of the disease. Staging involves more tests in a careful attempt to find out whether the cancer has spread and, if so, to which parts of the body. Knowing the stage of the disease helps the doctor plan treatment. Mesothelioma is described as localized if the cancer is found only on the membrane surface where it originated. It is classified as advanced if it has spread beyond the original membrane surface to other parts of the body, such as the lymph nodes, lungs, chest wall, or abdominal organs. How is mesothelioma treated? Treatment for mesothelioma depends on the location of the cancer, the stage of the disease, and the patient's age and general health. Standard treatment options include surgery, radiation therapy, and chemotherapy. Sometimes, these treatments are combined. Surgery is a common treatment for mesothelioma. The doctor may remove part of the lining of the chest or abdomen and some of the tissue around it. For cancer of the pleura (pleural mesothelioma), a lung may be removed in an operation called a pneumonectomy. Sometimes part of the diaphragm, the muscle below the lungs that helps with breathing, is also removed. Radiation therapy, also called radiotherapy, involves the use of high-energy rays to kill cancer cells and shrink tumors. Radiation therapy affects the cancer cells only in the treated area. The radiation may come from a machine (external radiation) or from putting materials that produce radiation through thin plastic tubes into the area where the cancer cells are found (internal radiation therapy). Chemotherapy is the use of anticancer drugs to kill cancer cells throughout the body. Most drugs used to treat mesothelioma are given by injection into a vein (intravenous, or IV). Doctors are also studying the effectiveness of putting chemotherapy directly into the chest or abdomen (intracavitary chemotherapy). To relieve symptoms and control pain, the doctor may use a needle or a thin tube to drain fluid that has built up in the chest or abdomen. The procedure for removing fluid from the chest is called thoracentesis. Removal of fluid from the abdomen is called paracentesis. Drugs may be given through a tube in the chest to prevent more fluid from accumulating. Radiation therapy and surgery may also be helpful in relieving symptoms. Are new treatments for mesothelioma being studied? Yes. Because mesothelioma is very hard to control, the U.S. National Cancer Institute (NCI) is sponsoring clinical trials (research studies with people) that are designed to find new treatments and better ways to use current treatments. Before any new treatment can be recommended for general use, doctors conduct clinical trials to find out whether the treatment is safe for patients and effective against the disease. Participation in clinical trials is an important treatment option for many patients with mesothelioma. Mesothelioma Links http://medicalwisdom.com/health/disorders/mesothelioma.htm The first version of this article was adapted from a public domain U.S. National Cancer Institute fact sheet at http://cis.nci.nih.gov/fact/6_36.htm This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License. Mesothelium The mesothelium is a membrane, derived from the embryonic mesoderm cell layer, that lines the coelom (body cavity) in the embryo. It becomes the layer of cells that covers and protects most of the internal organs of the body. It is composed of two layers of cells: One layer immediately surrounds the organ; the other forms a sac around it. The mesothelium produces a lubricating fluid that is released between these layers, allowing moving organs (such as the beating heart and the expanding and contracting lungs) to glide easily against adjacent structures. The mesothelium has different names, depending on its location in the body. The peritoneum is the mesothelial tissue that covers most of the organs in the abdominal cavity. The pleura is the membrane that surrounds the lungs and lines the wall of the chest cavity. The pericardium covers and protects the heart. The mesothelial tissue surrounding the male internal reproductive organs is called the tunica vaginalis testis. The tunica serosa uteri covers the internal reproductive organs in women. Mesothelioma (cancer of the mesothelium) is a disease in which cells of the mesothelium become abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Cancer cells can also metastasize (spread) from their original site to other parts of the body. Most cases of mesothelioma begin in the pleura or peritoneum. First version adapted from public domain material at http://cis.nci.nih.gov/fact/6_36.htm This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License. Asbestos Asbestos (Greek a-, "not"; sbestos, "extinguishable") is a group of fibrous metamorphic mineralss. Asbestos was historically used for lamp wicks from which the name derives. It was also in fabrics such as Egyptian burial cloths and Charlemagne's tablecloth which legend says he threw in a fire to clean. The fibres are typically mixed with cement or woven into fabric or mats. It is used in buildings for its flame-retardant and insulating properties, its tensile strength, flexibility, and its resistance to chemicals, but is now known to be carcinogenic and is banned in many countries. Types of asbestos Chrysotile, or white asbestos, is obtained from Canadian serpentine rocks. It is less friable, and therefore less likely to be inhaled, than the other types and is the type most often used industrially. Chrysotile should not be confused with chrysolite, a synonym of olivine. Amosite, or brown asbestos, is an amphibole from Africa. Crocidolite, or blue asbestos, is an amphibole from Africa and Australia. It is the fibrous form of riebeckite. Notes: Serpentine rocks are those with curled fibres. Amphiboles have straight, needle-like fibres. The amphiboles, in their fibrous form, are friable and therefore the most carcinogenic, although they also exist in safer non-fibrous forms. Other asbestos minerals, such as tremolite, actinolite and anthophyllite are not used industrially but occur in traces. Asbestosis and Cancer The fine asbestos fibres are easily inhaled, and can cause a number of respiratory complaints, including a potentially serious lung fibrosis asbestosis. Exposure to asbestos has also been determined to cause a very serious form of cancer, mesothelioma, that occurs in the chest and abdominal cavities. This aggressive disease is not properly referred to as a lung cancer, as the malignant cells are derived from the mesothelium, a tissue found on the inner walls of the chest and abdominal cavities and on the outer surface of the lungs rather than in the lung itself. In the United States, asbestos was one of the first hazardous air pollutants regulated under Section 112 of the Clean Air Act of 1970. See also: List of minerals, Eternit This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License. Asbestosis Asbestosis is a chronic inflammatory medical condition affecting the parenchymal tissue of the lungs. It is caused by the chronic inhalation of asbestos fibers. People at risk are with occupational exposure to the mining, manufacturing, handling or removal of asbestos. There is an increased risk of lung cancer and mesothelioma associated with asbestosis. The risk is related to the total dose of asbestos received and the duration of asbestos exposure. Exposure to the crocidolite form of asbestos is the form most associated with mesothelioma among the four forms of asbestos. Mesothelioma usually occurs between 20-40 years after exposure to asbestos and has a very poor prognosis with most patients dying within 2-4 years of diagnosis. Inhalation of fibers of asbestos lead to development of alveolar and interstitial fibrosis of lung tissue. This leads to reduced lung capacity and compliance, leading to reduced gas transfer. The primary symptom of asbestosis would be a slow, insidious onset of shortness of breath on exertion. In severe, advanced cases, this may lead to respiratory failure. Cough is not usually a typical symptom unless the patient has concomitant other respiratory tract diseases. Diagnosis of asbestosis is largely dependent on a good and accurate clinical history taking. Occupational exposure to asbestosis is critical to the diagnosis. Histopathological diagnosis is usually not necessary for patient management but can be used to confirm the diagnosis in post-mortem. Prevention of asbestosis involves identifying risk of exposure to asbestos and protection from dusts and inhaled substances at work. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License. Product liability Product liability is the holding of a manufacturer or other party liable for defects in its product that cause a legally recognizable injury. See also: Consumer protection This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License. Lung cancer Lung cancer is a malignant tumour of the lungs. Most commonly it is bronchogenic carcinoma (about 90%). Lung cancer is the most lethal malignant tumour worldwide, causing up to 3 million deaths. Exposure to carcinogens, such as those present in tobacco smoke, immediately causes small changes to the tissue lining the bronchi of the lungs (the bronchial mucous membrane). This effect is cumulative, and over time with continued exposure more and more tissue gets damaged until a tumour develops. If the tumour grows inwards it may obstruct the air passageway, causing breathing difficulties. The lungs may then collapse and infections can develop, leading to lung abscess. The patient here would start to cough up blood-stained material. However, if the tumour grows outwards in to the lung it may not even be noticed by the patient before it starts to spread to other parts of the body. Common symptons include: coughing up blood or lung-material bad, chronic, cough, wheezing, chest pains, weight loss or loss of appetite, shortness of breath. Table of contents 1 Types 2 Causes 3 Treatment 4 Susceptibility 5 Prevention Types There are two main types of lung cancer categorised by the size of the cancerous cells seen under a microscope: small and non-small cell lung cancer. Small cell types: Small cell carcinoma (also called oat cell carcinoma) is the less common form of lung cancer, making up 20% of cases. It tends to start in the larger breathing tubes and grows rapidly becoming quite large. Non-small cell types: Epidermoid carcinoma (or Squamous cell carcinoma) also starts in the larger breathing tubes but grows slower meaning that the size of these tumours varies when on diagnosis. Adenocarcinoma (or for slower growing forms alveolar cell cancer) is a form which starts near the surface of the lung. Large cell carcinoma is a fast-growing form that grows near the surface of the lung. The listed types add up to 90% of all cases of lung cancer. Other forms include carcinoid, cylindroma, mucoepidermoid and malignant mesothelioma. Causes There are four major reasons why people get lung cancer (and actually cancer in general): Carcinogens such as those contained in cigarretes Radiation Genetic susceptibility viruses Smoking, particularly of cigarettes, is believed to be by far the main cause of cancer, which in at least in theory makes it one of the easiest diseases to prevent. An estimated 80% of lung cancers result from smoking, due to the hundreds of known carcinogens, such as benzene, present in cigarette smoke. The length of time that a person continues to smoke as well as the amount smoked increases there chances of contracting lung cancer. However if someone stops smoking then these chances steadily decrease as the damage to their lungs is repaired. Passive smoking, whereby exhaled smoke is taken up by other people, has recently been identified as a much larger cause of lung cancer in non-smokers than previously believed. The US Environmental Protection Agency (EPA) in 1993 concluded that about 3,000 lung-cancer related deaths were caused by passive smoking every year, however the true extent is still being contested among scientists. Asbestos is another popularly known carcinogen mainly for mesothelioma (affecting the mesothelium lining lungs, abdomen or heart.) Often this exposure happens to people unavoidably through their work. Radon is a colourless and odorless gas derived from the breakdown of radioactive radium, which in turn is the decayed product of uranium, found in the earth's crust. It is the second major cause of lung cancer after smoking. This radiation ionises genetic material, causing mutations that sometimes become cancerous. Radon gas levels vary over where you live. In areas such as Cornwall in the UK, radon-gas is a major problem, and fans have to be installed to drive out the gas. In the US the EPA estimated that 1 in 15 homes have radon levels above the recommended standard. Oncogenes are genes which is believed make people more susceptible to cancer. Proto-oncogenes are believed to turn in to oncogenes when exposed to particular carcinogens. Viruses are suspected to cause cancer in humans, as this link has already been proven in animals. Treatment Treatments for lung cancer depends on the specific form, how far it has developed and on other details of the patient (eg. age). Common treatments include surgery, chemotherapy and radiation therapy. Radiofrequency Ablation is increasing in popularity for this condition as it is non toxic and causes very little pain. It seems especially effective when combined with chemotherapy as it catches the cells inside a tumor - the ones difficult to get with chemo due to a reduced bood supply to the inside of the tumor. It is done by inserting a small heat proble inside the tumor to cook the tumor cells. These are then disposed of by the body through normal eliminative processes. Other treatments include a variety of non patentable techniques often derived from native medical traditions - for instance fish oil. Fish oil prevents and reverses 'cachexia' - cancer weight loss. There are many such treatments listed on http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed where the research never reaches the double blind trial stage because no company spends millions of dollars testing the efficacy of something it cannot patent. A search there on 'tumor' and 'complete response' is enlightening when combined with the chemical names of substances from http://www.mnwelldir.org/docs/cancer1/altthrpy.htm Susceptibility The group most likely to develop lung cancer are the over-fifties who also have a history of smoking. Lung cancer is the second most commonly occurring form of cancer in most western countries, however it is the leading cancer-related cause of death for men and women. It is expected that in 2001 there will be 169,500 new cases of lung cancer; 90,700 in men and 78,000 in women. Although the rate of men dying from lung cancer is declining in western countries, it is actually increasing for women due to the increased take up of smoking in this group. Prevention Prevention plans are the most cost-effective means of fighting lung cancer on national and global scale. While in most countries industrial and domestic carcinogens have been identified and banned, tobacco smoking still is quite widespread. Fighting tobacco smoking should be primary goal for lung cancer prevention. Because prognosis depends heavily on early detection there have been several attempts at secondary prevention. Regular chest radiography and sputum examination programs were not effective in early detection of this cancer and did not resulted in reduction of mortality. However in September 2003 one study published in Lancet is quite promising. The study showed that spiral computed tomography and positron emission tomography were effective in detecting early stages of lung cancer in high risk poipulation of heavy smokers. Reference: Early lung-cancer detection with spiral CT and positron emission tomography in heavy smokers: 2-year results Lancet 2003; 362: 593-97 See also: Cancer -- Oncology -- Chemotherapy This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License. This page created and maintained by Jamie Sanderson. © Jamie Sanderson 1999-2005.