Asbestosis Mesothelioma Information

Mesothelioma and Asbestos

2011-12-28T03:33:00.000-08:00

Mesothelioma and asbestos, those two words can not be separated each other. People even call the disease as mesothelioma asbestos. Although it is a serious cancer, asbestos is the main trigger of the condition.

This product is a harmful fiber. Asbestos are formed into small pieces of materials and remain airborne for specific periods of time. Anyone who inhales asbestos, it is vulnerable to serious medical conditions such as mesothelioma cancer, asbestosis, and lung cancer.

Mesothelioma is connected to asbestos. The mesothelium cells are responsible to protect the vital organs such as hearth, lungs, and stomach inside the body. When it is affected by asbestos, it will lead to mesothelioma disaster. Mesothelioma is generally classified to 3 types: peritoneal mesothelioma, pericardial mesothelioma, and pleural mesothelioma.

The symptoms involving in the diseases are hard breathing, dramatic weight loss, coughing, chest pain, weakened musces, hoarseness, constipations, and etc. The most common form of meothelioma is pleural mesothelioma or cancers that affect the lungs. About 2 from 3 patients are suffering from pleural mesothelioma. It is all caused by exposure to asbestos for long period of time.

The hazard effects of longing contact with asbestos and the connection with mesothelioma cancer lead to several lawsuits against manufacturers that are suspected to expose the asbestos fibers to the working field. Lawyer mesothelioma is the crucial matter to consider once the patient diagnosed with mesothelioma need medical attention since the fund can not be covered by only one party, there must be responsible party (manufacturers) that handle the rest of the fiscal matters.

Overview of Malignant Mesothelioma

2011-12-28T03:30:00.000-08:00

Over a period of decades, folks have witnessed dreaded disease that is caused by repeatedly inhaled or ingestion of asbestos fibers, mesthelioma. The asbestos fibers are know as the harmful thing to develop this killing cancer along with the lung tissues. A variety of similar diseases are triggered by the prolonged and frequent exposure of asbestos fibers like malignant mesothelioma, asbestosis, and lung cancer. The most dangerous stage of these diseases is mesothelioma, which can lead the patients to the death.

Mesothelioma affects the lungs and the abdomen lining is very rare type of cancer and there is no cure for this disease so far. It is always triggered by the inhalation of asbestos for a long time, but can be spread to the weaker immune system and other internal infections may occur during the disgestion.

The impacts of this cancer attacks mostly people in the age range of 20 – 40 years old. And the development of mesothelioma may occur approximately 10 – 40 years after the victim inhaled the asbestos fibers. That is why it is hard to be diagnosed unless folks who work in the company that expose asbestos fibers realize that they can have chance to get mesothelioma and check themselves immediately without any further delay.

Earlier diagnosis and treatment are mandatory to increase the life expectancy after diagnosed with mesothelioma. We can not turn back time, all we can do just do the best to cope with the condition. Since it takes many years for malignant mesothelioma to develop and grow, there is some times to check our condition to the doctor.

Smoking and Mesothelioma

2011-12-28T03:26:00.000-08:00

Why the people always connect the smoking and mesothelioma? Are they really related to each other? First we should learn the fact that the implication of mesothelioma is too late to diagnose since the difficulty detecting symptoms make it hard for any specialist to detect except the patients are realizing that they are in the bad condition. When a patient is exposed to the asbestos materials, they will get a chance to have lungs cancer or mesothelioma.

Although smoking is considered as the dangerous thing in the case of lungs healthiness, it does not mean that smoking cause mesothelioma. In fact, it has nothing to do with mesothelioma. However, smoking will just severe an individual to chance of developing disease. Smoking may not cause mesothelioma cancer in the direct way, but it can cause other threatening condition of health such as lung cancer, emphysema and asbestosis. Asbestosis is actually not a mesothelioma cancer although people often consider it as the alias of mesothelioma, but it does help to develop the cancer in the body.

If a patient is diagnosed with mesothelioma cancer, it is crucial that they have to keep in mind to stop smoking immediately without any further delay. Although it does not make the mesothelioma, it can increase the possibility of developing lung cancer by 50 % or even more! A sufferer who is a smoker is seemed to be a prior person who gets chance to develop other lung-related diseases than an individual who have been exposed to asbestos fibers for several years. It proves that how serious the damage caused by smoking.

A smoker that has been exposed to asbestos fibers wherever he or she is, should get proper and immediate diagnosis before it is too late to realize that they are developing mesothelioma and other types of lung-related conditions.

Children with Mesothelioma

2011-12-28T03:22:00.000-08:00

Mesothelioma is an aggressive type of cancer caused by asbestos exposure. Generally this deadly cancer is found in elderly people and until a few years back, it was considered that children cannot get infected with mesothelioma. But recently children under the age of 10 have been diagnosed with mesothelioma. Since the prognosis is very poor, therefore doctors need to carefully diagnose mesothelioma in children.

Mesothelioma in Children – What are the Causes?
Mesothelioma can strike children but it is not clear yet how children get infected with asbestos and develop mesothelioma. When asbestos fibers enters the body, they become lodged within the lining of the lungs, abdomen, heart and other organs and take a lot of time to form mesothelioma cancer. Therefore, doctors believe that asbestos exposure is not the major cause of developing mesothelioma in children because of the long latency period of mesothelioma. However, few researchers believe that children may experience secondary asbestos exposure. It means individuals who worked at asbestos job sites brought home toxic dust on their clothes or in their hair. These fibers can be inhaled by children and become lodged in the chest or abdominal area, eventually causing the formation of mesothelioma cancer.

Studies of Children with Mesothelioma
Although, research is still going on in this area, but researchers have found the number of peritoneal mesothelioma cases in children. A recent study conducted on eight children with mesothelioma shows out of eight, five children developed peritoneal mesothelioma which attacks the abdominal lining. While three children showed pleural mesothelioma which attacks the lining of the lungs. This shows that mesothelioma can be found in children, although most victims are adults because it takes decades to manifest mesothelioma symptoms.

Symptoms of Mesothelioma in Children
Mesothelioma symptoms are non specific and are closely associated with common illnesses. Generally, children with mesothelioma often complained of pain from bloating, due to fluid build-up of their abdomen. Some common mesothelioma symptoms include:
Shortness of breath (dyspnea)
Difficulty breathing coughing
Chest pain
Abdomen pain
Weight loss
Husky voice
Difficulty swallowing
Fever
Anemia
Bowel obstruction
Inability to sleep
Loss of appetite
Since, mesothelioma symptoms are non specific; therefore it is advised to immediately contact your doctor to inform about any prior asbestos history so that early diagnosis can be made, especially in children as timely treatment can increase their life expectancy.

Diagnosing Children with Mesothelioma
It is extremely difficult to diagnose children with mesothelioma. Doctors generally don’t identify the disease when examining a child who is experiencing similar symptoms to those experienced by elderly mesothelioma patients. So, children with mesothelioma undergo a series of tests before actual diagnosis is made.

Treating Children with Mesothelioma
Since there are very few cases of mesothelioma reported in children, therefore there is no standard treatment method discovered for children with mesothelioma. Like in adults, oncologists usually recommend chemotherapy, radiation therapy or surgery as a treatment. But unfortunately, there is very poor prognosis for children with mesothelioma. However, researchers deem that they will find some effective ways in future that will result in better prognosis as well as will benefit children with mesothelioma.It can be extremely difficult for families to deal with children with mesothelioma. But you can save your loved ones suffering from mesothelioma by contacting a variety of resources that are available today to help families cope with mesothelioma cancer.

Most Mesothelioma Attacks The Lungs

2011-12-28T03:13:00.000-08:00

The most common form of mesothelioma comes with tumors found in the lungs. Approximately between 70 and 80% of mesothelioma patients have the cancer in their pleural, or lung, lining. A common misconception concerning mesothelioma is that the patient has to be exposed to asbestos in large quantities over many, many years. The truth is, mesothelioma can be contracted with very little exposure to asbestos.

The mechanism in which mesothelioma tumors form comes exclusively in the design of the asbestos fibers from a microscopic standpoint. When examined, the asbestos fibers resemble what could be described as a fishing hook or barb. It is with this mechanism that the fibers imbed into the lung tissues and settle, causing scarring over time. There is no way in which the asbestos fibers can be removed on their own. Coughing will not rid the fibers, nor will it cause the fibers to break free of the lung lining. Over time, the collection of these inhaled particles build up and the scarring eventually evolves into a tumor.
There are people who have been diagnosed with mesothelioma illness upwards of 30 years after their last exposure to asbestos or asbestos fibers. You do not have to have a history of working in direct contact with asbestos to be considered at risk. Children or spouses of industrial workers who may have borough asbestos fibers home on their clothes can also be at significant risk for contamination. As can people who went to school, were in hospitals, or who were incarcerated before the mind 1970s decision to restrict the ability to use asbestos-related materials in job sites, in manufacturing, and in the construction of homes and places of public domain. If for any reason you believe you may have been exposed to asbestos, you should schedule an examination with a physician.

Mesothelioma Lawsuit for Individuals

2011-12-28T03:10:00.000-08:00

Finding mesothelioma lawsuit is chief way to get the compensation for your asbestos exposure case leading to the mesothelioma disease. Though the process is sometimes hard, it is worthwhile at the result since the mesothelioma sufferers will get the adequate compensation for their cases.

Patients who have been diagnosed with the dreadful type of cancer mesothelioma illness have their very right to ask their case or claim the company where they had been working for their exposure experience. It is crucial to notice the difference between lung cancer and mesothelioma.

That way makes some individuals can not ask their case about mesothelioma claim. Lung cancer is the obstacle since chiefly many other triggers away from asbestos exposure can cause the disease. If the individuals propose the claim from the lung cancer lawsuits against the company, there are less results in compensation.

In many countries, there is quoted time for claiming for mesothelioma compensation to the company working with. One or two years are the limit time. It is crucial to notice the case as soon as possible after the patients ot diagnosed with mesothelioma so that they can get the lawyer in time to investigate the case in advance. The investigation time depends on the various things related to the work places patients have been working. It takes more time to investigate if the patients have been working in several different places. However, it is important to discuss with your reliable attorney as soon as you get diagnosed with mesothelioma.

Probably you think that hiring mesothelioma lawsuit can be expensive. However, chief patients and their relatives have received the benefits of using lawsuit service. If you win, the court will decide the amount of money to be paid by the company though probably the defendant may appeal. It is also possible to get smaller amount of money that you expect. To conclude, you should be ready for receiving any compensation for your claim.

Recognizing Advance Symptoms of Mesothelioma

2011-12-28T03:06:00.000-08:00

Mesothelioma symptoms are developed gradually. Earlier symptoms including cough, hardness in breathing, and chest pain chiefly make the patients confuse about their disease and tend to cure them with mediocre medication. That will just make mesothelioma more severe. However, those symptoms are often seen in the pneumonia case since the lung infections develop in the lungs. It is important for all people who work in the asbestos exposure work field to regularly check their lungs conditions to prevent or take care mesothelioma. Once symptoms are more developed then the cancer is advanced, the basic treatments become useless to be done.

In advance mesothelioma symptoms of pleural mesothelioma, back pain and chest pain commonly happen. Coughing blood may be present as well. Some patients also experience the swelling of the face and arms. Most of them face the problems like sensory loss and weakened muscles. Once they experience those symptoms, their activities are disturbed just for sure. In the advanced symptoms of peritoneal mesothelioma, abdominal symptoms become more severe. Some of patients experience swelling in the abdomen, pain, constipations, nausea and vomiting and loss of appetite. Breathing can become more difficult once the patients experience advanced symptoms of peritoneal mesothelioma. In the other side, advanced pericardial mesothelioma include the symptoms like coughing, worsening breathlessness, and chest pain under the ribs.

In chief stages of malignant mesothelioma, the symptoms like fever, fatigue, and dramatic weight loss are usually occurred. People diagnosed with advanced mesothelioma cancer are usually taken care by medical treatment namely palliative to cure the discomfort symptoms. The problems that make the patients hard to breath like pleural and abdominal fluid over collections can be drained. The palliative will prevent further collections of the substances and the collection of excessive fluid can be placed in the abdominal cavities. Surgery, radiotherapy, one or more anti-cancers drugs can be used to cope with advanced malignant mesothelioma.

Mesothelioma Surgery

2011-12-28T03:03:00.000-08:00

Mesothelioma is indeed rare form of cancer that can happen in many types of forms. It is common knowledge that mesothelioma is caused by the long period of time exposure to the asbestos. This group of natural fibers that are dangerous for human if they inhale it are rarely avoidable since the work field often performs such asbestos exposure. People mostly do not realize when they inhale fibers they fibers will become lodged in the lungs alveolus in the long period of time. Those fibers will make cells and tissue disturbed and trigger to advanced problem like mesothelioma. Pleural mesothelioma is the common name of the form of mesothelioma cancer that almost 75 per cent of patients experience this case.

The next common form namely peritoneal mesothelioma shows 20 per cent of all mesothelioma cases and remaining 5 per cent is crowned for pericardial mesothelioma. Pleural mesothelioma strikes to the lining of the lungs, peritoneal mesothelioma affects the peritoneum. All of the mesothelioma cases affects the important areas of the patients, making the disease difficult to treat with many medication attentions. Radiation therapy is one of the treatments is used but can only be operated with the strict radiation dosage since there is possibility in damaging important organs of the human in the procedure.

Those patients who are stronger since weaker mesothelioma sufferers have bigger risk of death after conducting the aggressive operations apply aggressive mesothelioma surgery. Experts and doctors will measure the strength of their patients before conducting aggressive surgery to them. They will consider information including disabilities, allergies, sex, medical records, and weight. With the aggressive surgery, there is a chance patients will die within the surgery operation.

Second type of surgery for mesothelioma is named palliative procedures. This way is less damaging and aggressive. However, this surgery just offers the patients to lessen the symptoms.

Defenition Of Mesothelioma

2011-12-28T02:28:00.000-08:00

Mesothelioma , more precisely malignant mesothelioma , is a rare form of cancer that develops from the protective lining that covers many of the body's internal organs, the mesothelium . It is usually caused by exposure to asbestos .
Its most common site is the pleura (outer lining of the lungs and internal chest wall), but it may also occur in the peritoneum (the lining of the abdominal cavity), the pericardium (a sac that surrounds the heart ),or the tunica vaginalis (a sac that surrounds the testis).
Most people who develop mesothelioma have worked on jobs where they inhaled asbestos, or they have been exposed to asbestos dust and fiber in other ways. It has also been suggested that washing the clothes of a family member who worked with asbestos can put a person at risk for developing mesothelioma. Unlike lung cancer, there is no association between mesothelioma and smoking , but smoking greatly increases the risk of other asbestos-induced cancers. Those who have been exposed to asbestos have collected damages for asbestos-related disease, including mesothelioma. Compensation via asbestos funds or lawsuits is an important issue in law practices regarding mesothelioma (see asbestos and the law ).
The symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall ) or chest wall pain , and general symptoms such as weight loss . The diagnosis may be suspected with chest X-ray and CT scan , and is confirmed with a biopsy (tissue sample) and microscopic examination. A thoracoscopy (inserting a tube with a camera into the chest) can be used to take biopsies. It allows the introduction of substances such as talc to obliterate the pleural space (called pleurodesis ), which prevents more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy , radiation therapy or sometimes surgery , the disease carries a poor prognosis . Research about screening tests for the early detection of mesothelioma is ongoing.

Signs and symptoms
Symptoms or signs of mesothelioma may not appear until 20 to 50 years (or more) after exposure to asbestos. Shortness of breath, cough, and pain in the chest due to an accumulation of fluid in the pleural space ( pleural effusion ) are often symptoms of pleural mesothelioma.
Symptoms of peritoneal mesothelioma include weight loss and cachexia , abdominal swelling and pain due to ascites (a buildup of fluid in the abdominal cavity). 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.
Mesothelioma that affects the pleura can cause these signs and symptoms:

Chest wall pain
Pleural effusion, or fluid surrounding the lung
Shortness of breath
Fatigue or anemia
Wheezing, hoarseness, or cough
Blood in the sputum (fluid) coughed up ( hemoptysis )

In severe cases, the person may have many tumor masses. The individual may develop a pneumothorax , or collapse of the lung . The disease may metastasize , or spread, to other parts of the body.
Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:

Abdominal pain
Ascites , or an abnormal buildup of fluid in the abdomen
A mass in the abdomen
Problems with bowel function
Weight loss

In severe cases of the disease, the following signs and symptoms may be present:

Blood clots in the veins, which may cause thrombophlebitis
Disseminated intravascular coagulation , a disorder causing severe bleeding in many body organs
Jaundice , or yellowing of the eyes and skin
Low blood sugar level
Pleural effusion
Pulmonary emboli, or blood clots in the arteries of the lungs
Severe ascites

A mesothelioma does not usually spread to the bone, brain, or adrenal glands. Pleural tumors are usually found only on one side of the lungs.

Cause
Working with asbestos is the major risk factor for mesothelioma. In the United States, asbestos is the major cause of malignant mesothelioma and has been considered "indisputably" associated with the development of mesothelioma. Indeed, the relationship between asbestos and mesothelioma is so strong that many consider mesothelioma a “signal” or “sentinel” tumor. A history of asbestos exposure exists in most cases. However, mesothelioma has been reported in some individuals without any known exposure to asbestos. In rare cases, mesothelioma has also been associated with irradiation, intrapleural thorium dioxide ( Thorotrast ), and inhalation of other fibrous silicates, such as erionite . Some studies suggest that simian virus 40 ( SV40 ) may act as a cofactor in the development of mesothelioma.
Asbestos was known in antiquity, but it was not mined and widely used commercially until the late 19th century. 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 publicly 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 official position of the US Occupational Safety and Health Administration (OSHA) and the US EPA is that protections and "permissible exposure limits" required by US regulations, while adequate to prevent most asbestos-related non-malignant disease, they are not adequate to prevent or protect against asbestos-related cancers such as mesothelioma.Likewise, the British Government's Health and Safety Executive (HSE) states formally that any threshold for mesothelioma must be at a very low level and it is widely agreed that if any such threshold does exist at all, then it cannot currently be quantified. For practical purposes, therefore, HSE assumes that no such "safe" threshold exists. Others have noted as well that there is no evidence of a threshold level below which there is no risk of mesothelioma. There appears to be a linear, dose-response relationship, with increasing dose producing increasing disease. Nevertheless, mesothelioma may be related to brief, low level or indirect exposures to asbestos. The dose necessary for effect appears to be lower for asbestos-induced mesothelioma than for pulmonary asbestosis or lung cancer. Again, there is no known safe level of exposure to asbestos as it relates to increased risk of mesothelioma.
The duration of exposure to asbestos causing mesothelioma can be short. For example, cases of mesothelioma have been documented with only 1–3 months of exposure. People who work with asbestos wear personal protective equipment to lower their risk of exposure.
Latency, the time from first exposure to manifestation of disease, is prolonged in the case of mesothelioma. It is virtually never less than fifteen years and peaks at 30–40 years. In a review of occupationally related mesothelioma cases, the median latency was 32 years. Based upon the data from Peto et al. , the risk of mesothelioma appears to increase to the third or fourth power from first exposure.

Environmental exposures
Incidence of mesothelioma had been found to be higher in populations living near naturally occurring asbestos. For example, in central Cappadocia , Turkey, mesothelioma was causing 50% of all deaths in three small villages — Tuzköy, Karain and Sarıhıdır. Initially, this was attributed to erionite , a zeolite mineral with similar properties to asbestos . Recently, however, detailed epidemiological investigation showed that erionite causes mesothelioma mostly in families with a genetic predisposition. The documented presence of asbestos fibers in water supplies and food products has fostered concerns about the possible impact of long-term and, as yet, unknown exposure of the general population to these fibers.

Occupational

Exposure to asbestos fibers has been recognized as an occupational health hazard since the early 20th century. Numerous epidemiological studies have associated occupational exposure to asbestos with the development of pleural plaques, diffuse pleural thickening, asbestosis, carcinoma of the lung and larynx, gastrointestinal tumors, and diffuse malignant mesothelioma of the pleura and peritoneum. Asbestos has been widely used in many industrial products, including cement, brake linings, gaskets, roof shingles, flooring products, textiles, and insulation.

Commercial asbestos mining at Wittenoom, Western Australia, occurred between 1945 and 1966. A cohort study of miners employed at the mine reported that while no deaths occurred within the first 10 years after crocidolite exposure, 85 deaths attributable to mesothelioma had occurred by 1985. By 1994, 539 reported deaths due to mesothelioma had been reported in Western Australia.

Paraoccupational secondary exposure

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 fibres, asbestos workers are usually required to shower and change their clothing before leaving the workplace.

Asbestos in buildings

Many building materials used in both public and domestic premises prior to the banning of asbestos may contain asbestos. Those performing renovation works or DIY activities may expose themselves to asbestos dust. In the UK use of Chrysotile asbestos was banned at the end of 1999. Brown and blue asbestos was banned in the UK around 1985. Buildings built or renovated prior to these dates may contain asbestos materials.

Diagnosis

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. A history of exposure to asbestos may increase clinical suspicion for mesothelioma. A physical examination is performed, followed by chest X-ray and often lung function tests . The X-ray may reveal pleural thickening commonly seen after asbestos exposure and increases suspicion of mesothelioma. A CT (or CAT) scan or an MRI is usually performed. If a large amount of fluid is present, abnormal cells may be detected by cytopathology if this fluid is aspirated with a syringe. For pleural fluid, this is done by thoracentesis or tube thoracostomy ( chest tube ); for ascites, with paracentesis or ascitic drain ; and for pericardial [ disambiguation needed ] effusion with pericardiocentesis . While absence of malignant cells on cytology does not completely exclude mesothelioma, it makes it much more unlikely, especially if an alternative diagnosis can be made (eg tuberculosis , heart failure ). Unfortunately, the diagnosis of malignant mesothelioma by cytology alone is difficult, even with expert pathologists.

Generally, a biopsy is needed to confirm a diagnosis of malignant mesothelioma. A doctor 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. Alternatively, the chest surgeon might directly open the chest ( thoracotomy ). If the cancer is in the abdomen, the doctor may perform a laparoscopy . To obtain tissue for examination, the doctor makes a small incision in the abdomen and inserts a special instrument into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary. Immunohistochemical studies play an important role for the pathologist in differentiating malignant mesothelioma from neoplastic mimics. There are numerous tests and panels available. No single test is perfect for distinguishing mesothelioma from carcinoma or even benign versus malignant.

Staging

Staging of mesothelioma is based on the recommendation by the International Mesothelioma Interest Group. TNM classification of the primary tumor, lymph node involvement, and distant metastasis is performed. Mesothelioma is staged Ia–IV (one-A to four) based on the TNM status.

Screening

There is no universally agreed protocol for screening people who have been exposed to asbestos. Screening tests might diagnose mesothelioma earlier than conventional methods thus improving the survival prospects for patients. The serum osteopontin level might be useful in screening asbestos-exposed people for mesothelioma. The level of soluble mesothelin-related protein is elevated in the serum of about 75% of patients at diagnosis and it has been suggested that it may be useful for screening. Doctors have begun testing the Mesomark assay which measures levels of soluble mesothelin -related proteins (SMRPs) released by diseased mesothelioma cells.

Pathophysiology

The mesothelium consists of a single layer of flattened to cuboidal cells forming the epithelial lining of the serous cavities of the body including the peritoneal , pericardial and pleural cavities. Deposition of asbestos fibers in the parenchyma of the lung may result in the penetration of the visceral pleura from where the fiber can then be carried to the pleural surface, thus leading to the development of malignant mesothelial plaques. The processes leading to the development of peritoneal mesothelioma remain unresolved, although it has been proposed that asbestos fibers from the lung are transported to the abdomen and associated organs via the lymphatic system . Additionally, asbestos fibers may be deposited in the gut after ingestion of sputum contaminated with asbestos fibers.

Pleural contamination with asbestos or other mineral fibers has been shown to cause cancer. Long thin asbestos fibers (blue asbestos, amphibole fibers) are more potent carcinogens than "feathery fibers" ( chrysotile or white asbestos fibers). However, there is now evidence that smaller particles may be more dangerous than the larger fibers. They remain suspended in the air where they can be inhaled, and may penetrate more easily and deeper into the lungs. "We probably will find out a lot more about the health aspects of asbestos from [the World Trade Center attack], unfortunately," said Dr. Alan Fein, chief of pulmonary and critical-care medicine at North Shore-Long Island Jewish Health System. Dr. Fein has treated several patients for "World Trade Center syndrome" or respiratory ailments from brief exposures of only a day or two near the collapsed buildings.

Mesothelioma development in rats has been demonstrated following intra-pleural inoculation of phosphorylated chrysotile fibers. It has been suggested that in humans, transport of fibers to the pleura is critical to the pathogenesis of mesothelioma. This is supported by the observed recruitment of significant numbers of macrophages and other cells of the immune system to localized lesions of accumulated asbestos fibers in the pleural and peritoneal cavities of rats. These lesions continued to attract and accumulate macrophages as the disease progressed, and cellular changes within the lesion culminated in a morphologically malignant tumor.

Experimental evidence suggests that asbestos acts as a complete carcinogen with the development of mesothelioma occurring in sequential stages of initiation and promotion. The molecular mechanisms underlying the malignant transformation of normal mesothelial cells by asbestos fibers remain unclear despite the demonstration of its oncogenic capabilities (see next-but-one paragraph). However, complete in vitro transformation of normal human mesothelial cells to malignant phenotype following exposure to asbestos fibers has not yet been achieved. In general, asbestos fibers are thought to act through direct physical interactions with the cells of the mesothelium in conjunction with indirect effects following interaction with inflammatory cells such as macrophages.

Analysis of the interactions between asbestos fibers and DNA has shown that phagocytosed fibers are able to make contact with chromosomes , often adhering to the chromatin fibers or becoming entangled within the chromosome. This contact between the asbestos fiber and the chromosomes or structural proteins of the spindle apparatus can induce complex abnormalities. The most common abnormality is monosomy of chromosome 22. Other frequent abnormalities include structural rearrangement of 1p, 3p, 9p and 6q chromosome arms.

Common gene abnormalities in mesothelioma cell lines include deletion of the tumor suppressor genes :

Neurofibromatosis type 2 at 22q12
P16 INK4A
P14 AR

Asbestos has also been shown to mediate the entry of foreign DNA into target cells. Incorporation of this foreign DNA may lead to mutations and oncogenesis by several possible mechanisms:

Inactivation of tumor suppressor genes
Activation of oncogenes
Activation of proto-oncogenes due to incorporation of foreign DNA containing a promoter region
Activation of DNA repair enzymes, which may be prone to error
Activation of telomerase
Prevention of apoptosis

Asbestos fibers have been shown to alter the function and secretory properties of macrophages, ultimately creating conditions which favour the development of mesothelioma. Following asbestos phagocytosis, macrophages generate increased amounts of hydroxyl radicals , which are normal by-products of cellular anaerobic metabolism. However, these free radicals are also known clastogenic and membrane-active agents thought to promote asbestos carcinogenicity. These oxidants can participate in the oncogenic process by directly and indirectly interacting with DNA, modifying membrane-associated cellular events, including oncogene activation and perturbation of cellular antioxidant defences.

Asbestos also may possess immunosuppressive properties. For example, chrysotile fibres have been shown to depress the in vitro proliferation of phytohemagglutinin-stimulated peripheral blood lymphocytes, suppress natural killer cell lysis and significantly reduce lymphokine-activated killer cell viability and recovery. Furthermore, genetic alterations in asbestos-activated macrophages may result in the release of potent mesothelial cell mitogens such as platelet-derived growth factor (PDGF) and transforming growth factor -β (TGF-β) which in turn, may induce the chronic stimulation and proliferation of mesothelial cells after injury by asbestos fibres.

Treatment

The prognosis for malignant mesothelioma remains disappointing, although there have been some modest improvements in prognosis from newer chemotherapies and multimodality treatments.Treatment of malignant mesothelioma at earlier stages has a better prognosis, but cures are exceedingly rare. Clinical behavior of the malignancy is affected by several factors including the continuous mesothelial surface of the pleural cavity which favors local metastasis via exfoliated cells, invasion to underlying tissue and other organs within the pleural cavity, and the extremely long latency period between asbestos exposure and development of the disease. The histological subtype and the patient's age and health status also help predict prognosis. The epithelioid histology responds better to treatment and has a survival advantage over sarcomatoid histology.

Surgery

Surgery, by itself, has proved disappointing. In one large series, the median survival with surgery (including extrapleural pneumonectomy ) was only 11.7 months.However, research indicates varied success when used in combination with radiation and chemotherapy (Duke, 2008). (For more information on multimodality therapy with surgery, see below). A pleurectomy/decortication is the most common surgery, in which the lining of the chest is removed. Less common is an extrapleural pneumonectomy (EPP), in which the lung, lining of the inside of the chest, the hemi- diaphragm and the pericardium are removed.

Radiation

For patients with localized disease, and who can tolerate a radical surgery, radiation is often given post-operatively as a consolidative treatment. The entire hemi-thorax is treated with radiation therapy, often given simultaneously with chemotherapy. Delivering radiation and chemotherapy after a radical surgery has led to extended life expectancy in selected patient populations with some patients surviving more than 5 years. As part of a curative approach to mesothelioma, radiotherapy is also commonly applied to the sites of chest drain insertion, in order to prevent growth of the tumor along the track in the chest wall.

Although mesothelioma is generally resistant to curative treatment with radiotherapy alone, palliative treatment regimens are sometimes used to relieve symptoms arising from tumor growth, such as obstruction of a major blood vessel. Radiation therapy when given alone with curative intent has never been shown to improve survival from mesothelioma. The necessary radiation dose to treat mesothelioma that has not been surgically removed would be very toxic.

Chemotherapy

Chemotherapy is the only treatment for mesothelioma that has been proven to improve survival in randomised and controlled trials. The landmark study published in 2003 by Vogelzang and colleagues compared cisplatin chemotherapy alone with a combination of cisplatin and pemetrexed (brand name Alimta) chemotherapy in patients who had not received chemotherapy for malignant pleural mesothelioma previously and were not candidates for more aggressive "curative" surgery. This trial was the first to report a survival advantage from chemotherapy in malignant pleural mesothelioma, showing a statistically significant improvement in median survival from 10 months in the patients treated with cisplatin alone to 13.3 months in the group of patients treated with cisplatin in the combination with pemetrexed and who also received supplementation with folate and vitamin B 12 . Vitamin supplementation was given to most patients in the trial and pemetrexed related side effects were significantly less in patients receiving pemetrexed when they also received daily oral folate 500mcg and intramuscular vitamin B 12 1000mcg every 9 weeks compared with patients receiving pemetrexed without vitamin supplementation. The objective response rate increased from 20% in the cisplatin group to 46% in the combination pemetrexed group. Some side effects such as nausea and vomiting, stomatitis , and diarrhoea were more common in the combination pemetrexed group but only affected a minority of patients and overall the combination of pemetrexed and cisplatin was well tolerated when patients received vitamin supplementation; both quality of life and lung function tests improved in the combination pemetrexed group. In February 2004, the United States Food and Drug Administration approved pemetrexed for treatment of malignant pleural mesothelioma. However, there are still unanswered questions about the optimal use of chemotherapy, including when to start treatment, and the optimal number of cycles to give. Cisplatin in combination with raltitrexed has shown an improvement in survival similar to that reported for pemetrexed in combination with cisplatin, but raltitrexed is no longer commercially available for this indication. For patients unable to tolerate pemetrexed, cisplatin in combination with gemcitabine or vinorelbine is an alternative, or vinorelbine on its own, although a survival benefit has not been shown for these drugs. For patients in whom cisplatin cannot be used, carboplatin can be substituted but non-randomised data have shown lower response rates and high rates of haematological toxicity for carboplatin-based combinations, albeit with similar survival figures to patients receiving cisplatin. In January 2009, the United States FDA approved using conventional therapies such as surgery in combination with radiation and or chemotherapy on stage I or II Mesothelioma after research conducted by a nationwide study by Duke University concluded an almost 50 point increase in remission rates.

Immunotherapy

Treatment regimens involving immunotherapy have yielded variable results. For example, intrapleural inoculation of Bacillus Calmette-Guérin (BCG) in an attempt to boost the immune response, was found to be of no benefit to the patient (while it may benefit patients with bladder cancer ). Mesothelioma cells proved susceptible to in vitro lysis by LAK cells following activation by interleukin-2 (IL-2), but patients undergoing this particular therapy experienced major side effects. Indeed, this trial was suspended in view of the unacceptably high levels of IL-2 toxicity and the severity of side effects such as fever and cachexia. Nonetheless, other trials involving interferon alpha have proved more encouraging with 20% of patients experiencing a greater than 50% reduction in tumor mass combined with minimal side effects.

Heated Intraoperative Intraperitoneal Chemotherapy

A procedure known as heated intraoperative intraperitoneal chemotherapy was developed by Paul Sugarbaker at the Washington Cancer Institute. The surgeon removes as much of the tumor as possible followed by the direct administration of a chemotherapy agent, heated to between 40 and 48°C, in the abdomen. The fluid is perfused for 60 to 120 minutes and then drained.

This technique permits the administration of high concentrations of selected drugs into the abdominal and pelvic surfaces. Heating the chemotherapy treatment increases the penetration of the drugs into tissues. Also, heating itself damages the malignant cells more than the normal cells.

This technique is also used in patients with malignant pleural mesothelioma.

Multimodality Therapy

All of the standard approaches to treating solid tumors—radiation, chemotherapy, and surgery—have been investigated in patients with malignant pleural mesothelioma. Although surgery, by itself, is not very effective, surgery combined with adjuvant chemotherapy and radiation (trimodality therapy) has produced significant survival extension (3–14 years) among patients with favorable prognostic factors. However, other large series of examining multimodality treatment have only demonstrated modest improvement in survival (median survival 14.5 months and only 29.6% surviving 2 years). [ 28 ] Reducing the bulk of the tumor with cytoreductive surgery is key to extending survival. Two surgeries have been developed: extrapleural pneumonectomy and pleurectomy/decortication. The indications for performing these operations are unique. The choice of operation depends on the size of the patient's tumor. This is an important consideration because tumor volume has been identified as a prognostic factor in mesothelioma. Pleurectomy/decortication spares the underlying lung and is performed in patients with early stage disease when the intention is to remove all gross visible tumor (macroscopic complete resection), not simply palliation. Extrapleural pneumonectomy is a more extensive operation that involves resection of the parietal and visceral pleurae, underlying lung, ipsilateral diaphragm, and ipsilateral pericardium. This operation is indicated for a subset of patients with more advanced tumors, who can tolerate a pneumonectomy.

Epidemiologi

Although reported incidence rates have increased in the past 20 years, mesothelioma is still a relatively rare cancer. The incidence rate varies from one country to another, from a low rate of less than 1 per 1,000,000 in Tunisia and Morocco, to the highest rate in Britain, Australia and Belgium: 30 per 1,000,000 per year. [ 38 ] For comparison, populations with high levels of smoking can have a lung cancer incidence of over 1,000 per 1,000,000. Incidence of malignant mesothelioma currently ranges from about 7 to 40 per 1,000,000 in industrialized Western nations, depending on the amount of asbestos exposure of the populations during the past several decades. It has been estimated that incidence may have peaked at 15 per 1,000,000 in the United States in 2004. Incidence is expected to continue increasing in other parts of the world. 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. Approximately one fifth to one third of all mesotheliomas are peritoneal.

Between 1940 and 1979, approximately 27.5 million people were occupationally exposed to asbestos in the United States. Between 1973 and 1984, the incidence of pleural mesothelioma among Caucasian males increased 300%. From 1980 to the late 1990s, the death rate from mesothelioma in the USA increased from 2,000 per year to 3,000, with men four times more likely to acquire it than women. These rates may not be accurate, since it is possible that many cases of mesothelioma are misdiagnosed as adenocarcinoma of the lung, which is difficult to differentiate from mesothelioma.

Society and culture

Notable cases

Mesothelioma, though rare, has had a number of notable patients.

Malcolm McLaren , former manager of New York Dolls and Sex Pistols , died on 8 April 2010.
Billy Vaughn , American bandleader, died in 1991.
Hamilton Jordan , Chief of Staff for US President Jimmy Carter and lifelong cancer activist, died in 2008.
Richard J. Herrnstein , psychologist and co-author of The Bell Curve , died in 1994.
Australian anti-racism activist Bob Bellear died in 2005.
British science fiction writer Michael G. Coney , responsible for nearly 100 works, also died in 2005.
American film and television actor Paul Gleason , perhaps best known for his portrayal of Principal Richard Vernon in the 1985 film The Breakfast Club , died in 2006.
Mickie Most , an English record producer, died of mesothelioma in 2003.
Paul Rudolph , American architect, died in 1997.
Bernie Banton , an Australian workers' rights activist, fought a long battle for compensation from James Hardie after he contracted mesothelioma after working for that company. He claimed James Hardie knew of the dangers of asbestos before he began work with the substance making insulation for power stations. Mesothelioma eventually took his life along with his brothers and hundreds of James Hardie workers. James Hardie made an undisclosed settlement with Banton only when his mesothelioma had reached its final stages and he was expected to have no more than 48 hours to live. Australian Prime Minister Kevin Rudd mentioned Banton's extended struggle in his acceptance speech after winning the 2007 Australian federal election .
Actor Steve McQueen was diagnosed with peritoneal mesothelioma on December 22, 1979. He was not offered surgery or chemotherapy because doctors felt the cancer was too advanced. McQueen subsequently sought alternative treatments at clinics in Mexico. He died of a heart attack on November 7, 1980, in Juárez, Mexico , following cancer surgery. He may have been exposed to asbestos while serving with the US Marines as a young adult—asbestos was then commonly used to insulate ships' piping—or from its use as an insulating material in automobile racing suits (McQueen was an avid racing driver and fan).
United States Congressman Bruce Vento died of mesothelioma in 2000. The Bruce Vento Hopebuilder award is given yearly by his wife at the MARF Symposium to persons or organizations who have done the most to support mesothelioma research and advocacy.
Rock and roll musician and songwriter Warren Zevon , after a long period of untreated illness and pain, was diagnosed with inoperable mesothelioma in the fall of 2002. Refusing treatments that he believed might incapacitate him, Zevon focused his energies on recording his final album The Wind , including the song "Keep Me in Your Heart," which speaks of his failing breath. Zevon died at his home in Los Angeles, California, on September 7, 2003.
Christie Hennessy , the influential Irish singer-songwriter, died of mesothelioma in 2007, and had stridently refused to accept the prognosis in the weeks before his death. Hennessy's mesothelioma has been attributed to his younger years spent working on building sites in London .
Bob Miner , one of the founders of Software Development Labs , the forerunner of Oracle Corporation , died of mesothelioma in 1994.
Scottish Labour MP John William MacDougall died of mesothelioma on August 13, 2008, after fighting the disease for two years.
Australian journalist and news presenter Peter Leonard of Canberra succumbed to the condition on September 23, 2008.
Terrence McCann , Olympic gold medalist and longtime Executive Director of Toastmasters , died of mesothelioma on June 7, 2006, at his home in Dana Point, California.
Merlin Olsen , Pro Football Hall of Famer and television actor, died on March 10, 2010, from mesothelioma that had been diagnosed in 2009.
Australian actor Harold Hopkins , who appeared in films such as The Club , Don's Party , Gallipoli ,and the TV mini series Sara Dane died from mesothelioma on December 11, 2011 in a Sydney hospital.

Notable people who have lived for some time with mesothelioma
Although life expectancy with this disease is typically limited, there are notable survivors. In July 1982, Stephen Jay Gould was diagnosed with peritoneal mesothelioma . After his diagnosis, Gould wrote "The Median Isn't the Message" for Discover magazine, in which he argued that statistics such as median survival are just useful abstractions, not destiny. Gould lived for another 20 years, eventually succumbing to metastatic adenocarcinoma of the lung, not mesothelioma. Author Paul Kraus was diagnosed with peritoneal mesothelioma in July 1997. He was given a prognosis of less than a year to live and used a variety of complementary modalities. He continued to outlive his prognosis and wrote a book about his experience "Surviving Mesothelioma and Other Cancers: A Patient's Guide" in which he presented his philosophy about healing and the decision making that led him to use integrative medicine .