Mesothelioma Gene Therapy

Malignant Pleural Mesothelioma

Malignant Pleural Mesothelioma is showing low survival rate regardless of tumor stage at diagnosis. Malignant Mesothelioma does not respond to treatments and new protocols are badly needed there. The localized nature, the potential availability and the relative lack of distant metastases of malignant mesothelioma is a particularly attractive candidate for somatic gene therapy.

A common goal for the treatment of cancer, the p53 tumor suppressor protein. P53 does not appear to be mutated or deleted in malignant mesothelioma, but it can bind to other proteins, such as inactivated MDM2 and SV40 large T antigen

It tested the effect of a replication-deficient adenoviral vector, the cDNA of wild-type p53 in human cells, malignant mesothelioma. Our results indicate that over 95% of malignant mesothelioma cells efficiently with 25 multiplicity of infection (MOI) of infected vector.

P53 wild type was actually expressed> 80% inhibition of cell proliferation in malignant mesothelioma cells. AdCMV.p53 infection-induced apoptosis, whereas controls showed no obvious morphological change.

Ex vivo gene transfer, p53 inhibited tumor growth in nude mice. Arrested in vivo by direct intratumoral injection AdCMV.p53 of tumor growth and prolonged survival time of treated mice. These results strongly indicate that p53 gene therapy to be used for clinical trials of patients with malignant mesothelioma. By Monty Wrobleski.

How to Avoid Mesothelioma

Below are some questions and answers that will explain to avoid Mesothelioma.


Not many people heard of Mesothelioma and are unaware of their symptoms. The disease is considered a cancer which are difficult to find, but the number of cases each year continues to increase. Prevalence rate of this disease is very large so it is important to understand what, why and how Mesothelioma develops.


Meaning of Mesothelioma

Mesothelioma is a malignant (cancerous). The Cancer cells are found in the mesothelium, it is a protective sac that covers most organs in the body. These cancer cells often attacks the lungs, heart and abdominal organs. The most common form is pleural mesothelioma. Pleural Mesothelioma is cancer of the lining of the lungs. And cancer cells can be found in the lining of the abdominal cavity (peritoneum) and the layer around the heart (pericardium).

Causes of Mesothelioma

Mesothelioma is usually caused by asbestos. Asbestos material is often found in pipes, boiler insulation, floor, ceiling and roof tiles. Asbestos material is in the environment such as asbestos mills, mines, shipping yards, some Navy ships or even older patients at home. About 3000 cases of mesothelioma per year are currently being diagnosed. Family members of workers exposed to asbestos can also contract this disease through exposure to workers' clothing. Like other cancers, smoking greatly increases the risk of contracting mesothelioma.

Volume of Asbestos that will Cause Mesothelioma

The development of this cancer are directly related to length of time you are exposed to asbestos. And health risks also increased with the intensity of exposed asbestos. A presentation stating that only one or two months exposed to asbestos, can cause mesothelioma in 30 or 40 years later.

That are some points to explain how to avoid Mesothelioma

An Example of Treatment Difficulties of Mesothelioma

Smoking is a rare cancer is contact asbestos. This disease is a cruel cancer types, because it is hard to find, often only diagnosed late stage. At this point, the treatment is usually very difficult. Give your idea, we have a job how difficult it is, in this article. The complication,

This is mesothelium cancer entry. This mesothelium found is a kind of lining the chest and abdomen, is more or less protection organs of scabbard, such as the heart and lungs. Although cancer easily recognizable, cannot say so, in thin lining around it. This is what makes mesothelioma so deadly. It is usually very late, usually found in has grown up to 20, 30, 40 years or longer.

Cancer is the most commonly found in mesothelioma lung. The doctor�s diagnosis, usually must undergo biopsy material. It is through the creation of a small incision, then insert the relevant medical instrument. Small amounts of substances are cut off, and then sent to the office and pathology in microscope examination. It sounds simple, but here is to cope with this. new

Surgeons have noticed a unique problems, this form of cancer. To perform a biopsy, a cancer often take the invasion of the incision. Cancerous growths and sprout, began to flourish. Consider, for one minute. This kind of cancer is so difficult, making an incision can spread. Facing this huge problems, you can understand why less than 10% of the patients survived 5 years.

Smoking is a rare disease, but a vicious circle. Treatment is improving, but no cure, has found that one is on the horizon. In this case, it is clear that should prohibit partial asbestos into a complete ban, absolutely, more and more people suffer.

Source : Meso

Treatment of Traditional Mesothelioma

Traditional treatment is the standard treatment for malignant mesothelioma entry, this is a kind of disease, cancer cells and tissues of the body mesothelial effect. Mesothelioma treatments because of different factors, such as the position of cancer cells, and the patient�s disease, a personal choice. Generally speaking, the traditional surgery, chemotherapy and radiotherapy, including mesothelioma or different combinations, these 3 kinds of treatment.

Surgical treatment of cancer, or delete the affected organ or alleviate pain. Sometimes it may not be able to remove all the parts, almost has spread, However surgery may help to relieve pain. Two categories, including �lung surgery� and �palliative program.�

Pneumonectomy involves lung. This method in two varieties, �traditional� lesions resected lung cancer is removed, and extrapleural lung �in� poor pulmonary and parts, the diaphragm and parietal pericardium pleural side with the chest, has been cancelled.

Application procedures, treatment, but cannot heal mesothelioma symptoms to relieve pain and control. �Thoracentisis� and �pleurectomy/decortication� is all sorts of palliative program. In thoracentisis, a needle is on the chest, either from liquid to diagnose, or from liquid to alleviate pain. Pleurectomy/decortication remove pleural to alleviate the pain or prevent recurrence of pleural effusion.

Chemotherapy is another important traditional treatments used to kill cancer cells of the entry into the intravenous drugs. This method also involves the use of drugs to maintain normal tumor cells. Quite serious side effects, but in the treatment of chemotherapy, and may even damage because of cancer cells, but health. Nausea, vomiting, fatigue, loss, constipation, decreased appetite and oral ulcer is some of its effects.

Radiation therapy (radiotherapy or treatment with high-energy rays) (such as X-ray) to destroy the cancer cells in the local area. Entry Although healthy cells would also be affected, they can more effectively repair themselves. Radiation effects include as a kind of traditional treatment mesothelioma fatigue, hair, skin allergy, nausea and breathing difficulties.

Source : Meso

Mesothelioma Cancer Treatment

Cancer is a kind of disease, mesothelioma from exposure

To the relevant material asbestos. Asbestos fiber, usually by then
Enter the body through the mouth or skin, then enter
Lung and blood.

Mesothelioma cancer has become more widely in the record last 5-10 years,
Due to the symptoms of asbestos cancer between 20 to 40 years for
To manifest. Cancer is difficult to diagnose mesothelioma symptoms, such as no tendency
Until then show their disease. Symptoms,
Mesothelioma lung cancer has shortness of breath, chest pain, fever and other
Minor illnesses such as pneumonia.

The most commonly occurs in the asbestos cancer men between the ages of 50-70 years old
Who were exposed to high levels of asbestos in the workplace. Asbestos is
Mainly used in manufacturing industry, such as automobile, shipbuilding
In the construction industry. With asbestos is only recently
In 1990.

Mesthelioma lung cancer has been found to be the most common form
It happened in the lung cancer and pleural mesothelioma (.).
Cancer can also mesothelioma abdominal peritoneum) (
In the heart (pericardial). Have a greater chance of malignant
Abdominal asbestos cancer. For a more detailed explanation of smoking
Cancer,

Smoking can be detected by lung CT scan, make it
Sometimes the diagnosis of early than the other two types of mesothelioma cancer.
This type of cancer therapy depends on the stage of cancer. Entry
The patient was diagnosed, age and individual be fond of. Alzheimer�s disease
Four different stage division. At this stage of the process, reached the disease
Cancer treatment method to determine the entry. In the first stage
Cancer of the lungs, only can attempt to remove surgeon
Surgical resection of the tumor. Once the tumor into the surrounding the body
In a later period, it cannot be cured.

Generally speaking, the more advanced mesothelioma
Cancer treatment is radiation and chemotherapy. Radiation,
Using high energy X-ray destroy cancerous cells treated with contraction
Cancer chemotherapy, on the other hand, the use of drugs to destroy the cancer cells.
The aim is to extend the entry of cancer therapy the patient�s life
Because of the more advanced disease can not be cured.

Besides the traditional mesothelioma cancer treatment, also have
Currently investigating different experimental treatments with new
Hope.

This form of biological immune: treatment mesothelioma cancer treatment
Using the patient�s own immune system to recognize and attack cancer cells. Clinical research,
The immune system that can distinguish healthy cell tumor cells,
So can be used to destroy the cancer cells.

Gene therapy: this type of cancer therapy is still in the entry
Stage of development. This course includes into a particular genes
Into the tumor. The genes that cancer cells sensitive
Glanciclovir antiviral drugs, in normal circumstance is not practical
According to these cells. This glanciclovir can destroy all the cancer
No damage healthy tissue cells.

Drug treatment of symptomatic only: drug approved drugs
The us food and drug administration (FDA) for the treatment of patients with malignant tumor
Mesothelioma lung cancer. This new and exciting drugs has been proved in practice
Test, reducing symptoms and increase the patients.

Photodynamic therapy: photodynamic therapy including use
Light to kill cancer cells. Patient first
Photosensitizing drugs, only collect in cancer cells. Optical fiber cable
Then insert the body, so that the frequency of light must focus
Tumor. Light stimulates photosensitizing toxic oxygen molecule drugs
The destroy cancerous cells.

These experiments, although still mesothelioma cancer treatment in development,
Cancer patients to provide better prospects and long service life. with
The possibility that more and more people have been diagnosed with asbestos
Cancer, further research for other forms of cancer therapy mesothelioma
Is of vital importance.

Source : Meso

Treatments of Mesothelioma

Malignant mesothelioma treatments may be difficult, all kinds of reasons. First, to correct diagnosis, entry may not appear in a patient for decades. This could cause problems with the processing, because, like all mesothelioma of cancer therapy is more difficult, and are no longer allowed to the progress of the disease. In addition, caused by delay treatment of difficulty, this disease is usually mesothelioma should not traditional cancer therapies, more complex treatment. At the same time, the agency, involving mesothelioma cannot bear part or the whole of the removed usually, it means surgical options can be very limited. Finally, the fact that most of the male patients with advanced international level of smoking older than 50 years, usually means that the more radical therapy can be used, because fall because of the health old.

Altogether, this means that even mesothelioma patients, recently diagnosed can get quite a negative outcome doctos from them. Statistics is difficult, but British scientists think 10% of the patients newly diagnosed with at least 3 years of entry, Only 5% of the live for five years or longer. In the first stage, 50% of patients live for at least two years. But doctors may be wrong, and diagnosed mesothelioma is not always equal death. In the case of a famous scientist Stephen jay gould, live peritoneal mesothelioma nearly 20 years. Finally, he died of another kind of cancer.

The four stages of disease malignant mesothelioma measurement has been improved. How to treat patients mesothelioma depends largely on which stage, he or she�s sick.

I: local mesothelioma * stage, only exist in lung, diaphragm and pericardium lining.

The second stage: advanced mesothelioma sexually transmitted to the lymph nodes in the chest.

Stage 3: advanced mesotheioma * has spread to the chest wall, chest, heart and diaphragm. The third stage malignant mesothelioma may or may not has spread to lymph nodes.

* 4: advanced mesothelioma is spread to other organs in the chest and abdomen.

Surgery,

Example 1) or mild second stage mesothelioma is usually provide one or more traditional cancer therapy: surgery, radiotherapy and chemotherapy. For early surgery patients, the disease is cured by literally entry cutting of cancer patients. The most common surgery is a pleurectomy pleural mesothelioma or decortication and this is doctor remove all or part of a lung tissue and chest. If doctors found that they cannot eliminate cancer and dismantling of lung tissue, they may also removed a pneumonectomy under, This is called. A more radical types of surgical treatment of pleural mesothelioma called extrapleural pneunonectomy (EPP). In this case, the surgeon will remove a subpleural lung cancer and a heart of inner diaphragm,. It is dangerous and difficult types of surgery, the surgeon will recommend or light.

This kind of influence, peritoneal mesothelioma abdominal surgery patients could give cytoredutive. In the surgery, doctors are trying to remove all the cancerous tissue they can find his belly and viscera. Doctors also can choose peritonectomy throughout the abdomen will be removed. Again, this isn�t an easy surgery and may not be suitable for every man, but it has successfully some patients. Cardiac patients undergoing surgery is generally entry.

Radiation and chemotherapy

In addition, or instead of the surgery, doctors will give patients with early mesothelioma chemotherapy and radiotherapy or both. Radiation and chemotherapy are used to kill cancer patients without killing. Unfortuantely, in order to kill cancer cells, these people often kill healthy cells. This is why cancer patients often lose their hair, diet, and generally weak and sick. The doctor prescribed of chemotherapy and radiation may also suggest nutritional supplements or other measures to control these symptoms.

Chemotherapy is any treating patients is specially designed to chemical drug therapy of cancer cells attack experience. This drug is injected into the blood often swallowing or in weeks or months later, in a loop, and give some patients recover time during treatment. Patients can stay at home, only need to visit your doctor�s office, they can be treated, Sometimes even treatment at home. In some cases, doctors can choose chemotherapy drugs, it needs directly carcinoma patients who, so must live in a hospital. There are many different kinds of chemotherapy drugs, scientists are trying to develop better every day.

Radiation therapy, aims to kill cancer cells and high-energy rays radiation, such as x-rays, prevent them grow. Patients with external-beam radiotherapy, directed by director certain parts of the body ray radiation is affected by cancer. This treatment lasts about 30 minutes a day, is in the same every day after a few weeks. In brachytherapy (internal, the doctor beside a container of radioactive substances of cancerous tissue, surgery, or existing in the body cavity. Some, others will be removed, replaced. Finally, radiopharmaceuticals is sometimes used to execute the radiation therapy, or injections into the body cavity or swallowed.

Source : Meso Info

Three Types of Malignant Mesothelioma

Mesothelioma cell lines the inside chest and abdomen, as well as heartfelt bag - the cavity around the heart. These cells are also lines the surface of most internal organs.


Fabric formed mezotelialnymi cells is called mezoteliya. Mezotely chest called pleurisy, abdominal - ventral cavity and heart - pericardium. Tumors mezoteliya are benign and malignant, and usually there are malignant tumors, called mesothelioma.






There are three types of malignant mezoteliom:
1. Epitelioidny type of 50-70% of all mezoteliom and with the best prognosis (outcome).


2. Sarkomatoidny type (7-20%).


3. Mixed type (20-35%).


Nearly 3 / 4 mezoteliom occurs in the thoracic cavity and are called the pleura mezoteliom. In 10-20% of the tumor develops in the abdomen - mesothelioma peritoneum. Mesothelioma pericardiocentesis occur very infrequently.


How frequently malignant mesothelioma occur?
Mesothelioma is a rare tumor, which is more common in men after 50 years. Every year thousands of new evidence of 2-3 cases. The tumor may be a long time, asymptomatic, and therefore is often detected at later stages, which negatively influences the prognosis (outcome) of disease. The average survival rate of patients is usually only 1-2 years.


Risk factors of malignant mesothelioma.
Exposure to asbestos is a major risk factor for mesothelioma. Asbestos is used in the manufacture of insulation and fire-resistant materials, tiles, brake pads, etc. Once the relationship of contact with asbestos and mesothelioma development of this substance has been dramatically reduced.
The risk of developing mesothelioma depends on the intensity and duration of exposure to asbestos. Prolonged contact at a young age greatly increases the risk of mesothelioma. The time period from the time of first contact with asbestos before the diagnosis of tumors is 20-50 years.


Smoking by itself does not affect the increase in the development of mesothelioma, but the combination of smoking and asbestos exposure significantly increases the risk of developing lung cancer. A smoking people exposed to asbestos, the risk of developing lung cancer increased in the 50-90 times compared with the general population.


To prevent (prevent) the development of mesothelioma must be taken to avoid contact with asbestos at home and at work.




Diagnosis of mesothelioma
Early symptoms mezoteliom are not specific. They are sometimes ignored or taken for patients of normal neopuholevyh diseases. Most patients with mesothelioma symptoms appear in 2-3 months to identify the tumor. A number of patients with symptoms may continue for 6 months or more.


50% of patients with mesothelioma pleura note at the bottom of a chest pain in the side or rear surface. Many patients complain of shortness of breath. In some cases, there is difficulty swallowing, coughing, sweating, weakness, weight loss and increased temperature. Other symptoms can indicate osiplost voice, hemoptysis, swelling of the face and upper limbs.


Patients with mesothelioma peritoneum possible abdominal pain, nausea, vomiting, weight loss. Some patients may receive the fluid in the abdomen (ascites) and / or swelling.


If you like mezoteliomu is an urgent need to consult a doctor to ascertain the presence of risk factors and appoint survey. During the examination the doctor can detect the presence of fluid in the pleural cavity (pleurisy), abdomen (ascites) or perikarde (pericarditis), which occurs as a result of the development of tumors.


Chest x-ray can detect thickening of pleura, the presence of kaltsifikatov (mineral deposits) in plevre and fluid in the pleural cavity.


Computer tomography (CT) makes it possible to diagnose mesothelioma and to determine the prevalence of (stage).


Magnetic resonance imaging (MRI) can help identify lesions diaphragm - the muscle tissue, which separates the chest and abdominal cavity.


Thoracoscopy (examination of pleural cavity with a special device) you can not only identify the tumor, but also to make a biopsy (take a piece of tissue for research) or to obtain fluid for microscopic studies to clarify the diagnosis.


Laparoscopy (abdominal examination with the help of the device) you can examine the abdominal cavity, take a piece of the tumor, or fluid for research.




Stages (prevalence), mesothelioma
Currently, only differentiated stage mesothelioma pleura, as occurs much more frequently than others localizations. There are 4 stages pleura mesothelioma.


Stage I - the tumor affects plevru the left or right, and the lymph nodes in the process is not involved.


Stage II - one-sided defeat of pleura and the spread of tumor in the diaphragm or lung tissue.


Stage III - one-sided defeat of pleura and distribution process on the front chest wall, or fatty tissue mediastinum, or pericardium, or lymph nodes on the side of mesothelioma.


Stage IV - mesothelioma involved in muscle or ribs, or sprouts diaphragm, or esophagus, trachea, thymus, the major blood vessels, or spine, or moving to the other side, or distributed through the bloodstream to distant organs.


Treatment of malignant mesothelioma
The choice of treatment depends on several factors including the stage of the tumor, the general condition of the patient and his views. Given the rarity of mesothelioma, it is advisable to carry out specialized cancer treatment facilities that have experience in the treatment of such patients.
Surgical treatment
The operation can be performed as a palliative or therapeutic purposes. A palliative operation meant surgery, which can eliminate or reduce pain or discomfort caused by the growth of tumors. Such operations are used when it is impossible to remove a tumor because of the prevalence of the condition of the patient or heavy.


Plevroektomiya / decortication is generally palliative operation is to remove the pleura, which prevents the accumulation of fluid and reduce the pain.


Torakotsentez - a procedure in which a needle is removed from the liquid from the pleural cavity to facilitate the patient's condition.


The introduction of talc or antibiotics in the pleural cavity in order to temporarily prevent the accumulation of fluid in the well in 90% of patients with mesothelioma pleura.


Puncture the front abdominal wall allows you to remove the accumulated fluid in the abdomen in patients with mesothelioma peritoneum.


Patients with mesothelioma pericardiocentesis pericardiocentesis execution provides an opportunity to remove fluid and improve the heart's activity.


Patients in a satisfactory condition with a localized tumor, performing radical surgery, ie complete removal of mesothelioma.
One should bear in mind that often, after the alleged radical operations are microscopic tumor foci. In this regard, the importance of radical operations in patients with mesothelioma contested.


Vneplevralnaya pneumonectomy is the removal of pleura, diaphragm, pericardiocentesis and light on the side of destruction. This extended operation can be performed only highly trained surgeons, oncologists in the patients with good general condition with severe concomitant diseases.


In patients with localized mezotelimoy peritoneum may be an attempt to remove a tumor along with part of the abdominal wall. Unfortunately, most patients with mesothelioma peritoneum performance of radical operations can not be in the prevalence of the process.


In the case of localized lesions pericardiocentesis performed his disposal, and in the dissemination process - palliative intervention to prevent the accumulation of fluid.




Radiation therapy
External radiation is used in patients with mesothelioma frequently.
With internal radiation radioactive material is brought directly to the tumor.
This type of radiation therapy is used as the primary method of treatment for patients in serious condition, when they can not move a serious operation.


Supporting radiotherapy after non appointed operations to destroy the remaining cancer cells.
Palliative irradiation is used to alleviate symptoms caused by the growth of tumors: shortness of breath, pain, bleeding and difficulty swallowing.


Radiation therapy can cause adverse reactions and complications in the form of burning the skin, weakness, nausea, vomiting, liquid stool, damage lung tissue, difficulty breathing.
Most adverse events being held after the completion of the course of irradiation.
It is known that radiation therapy may increase the side effects of chemotherapy.




Chemotherapy
When treating patients with malignant mesothelioma drugs could be imposed not only intravenously, but intrapleural and vnutriperitonealno (in the abdominal cavity).
Depending on the stage of tumor chemotherapy can be both substantive and supportive treatment. Moreover, chemotherapy is used only as a palliative, giving only a temporary effect.
Of the anticancer drugs used: doxorubicin, cisplatin, methotrexate, vinorelbin and others in various combinations.


On the adverse reactions of chemotherapy include: nausea, vomiting, loss of appetite, hair loss, the appearance of ulcers in the mouth, increased susceptibility to infections, bleeding. Most adverse events being held after completion of treatment.

Source : Over Mesothelioma

Risk Factors for Malignant Mesothelioma?

What are the risk factors for malignant mesothelioma?

There are several risk factors that increase the likelihood that a person will develop mesothelioma. The primary risk factor is asbestos exposure. Exposure to this very harmful substance can significantly enhance the chances of contracting the disease. Other secondary factors include exposure to radiation, zeolite, simian virus 40 (SV40) and tobacco. We discuss each of these risk factors in more detail below.

Asbestos

Exposure to asbestos is the leading risk factor associated with mesothelioma. Asbestos is an insulating material comprised of magnesium-silicate mineral fibers. It was favored by builders and contractors for many years for its low heat conductivity and resistance to melting and burning. Since researchers have identified more and more links between mesothelioma and exposure to asbestos, the material is now less widely used. Prior to this discovery, however, millions of Americans have experienced serious exposure to this harmful substance.

Over 700,000 schools and buildings in the United States today contain asbestos insulation as reported by the US Environmental Protection Agency. Asbestos exposure doesn�t stop there, however. Asbestos is often found in ship yards, manufacturing facilities, railway facilities and construction sites. Blue collar workers are at the highest risk for developing mesothelioma due to occupational exposure and include those who work in mines, factories, shipyards, construction sites, railroads and for insulation manufacturers and gas mask manufacturers. The occupations most widely affected are miners, factory workers, railroad workers, ship builders and construction workers - especially those who install asbestos containing insulation. Sometimes family members related to the workers receive second hand exposure to asbestos from the dust and fibers that were brought home on the workers clothes and also become at risk for contracting mesothelioma.

Serpentine fibers and amphiboles are the 2 primary types of asbestos used. Chrysotile is a form of serpentine fiber and the most frequently used. These fibers tend to be curly and flexible. Amphibole fibers, however, are generally straight and thin and usually comprise one of five types: crocidolite, amosite, anthrophylite, tremolite, and actinolyte. The crocidolite type of Amphiboles is thought to be the leading contributor to cancer caused by asbestos. Serpentine fibers are dangerous as well, however, and have also been linked to mesothelioma.

Some research points to the fact that inhaled asbestos fibers cause a physical irritation resulting in cancer rather than the cancer being caused by a reaction that is more chemical in nature. As fibers are inhaled through the mouth and nose they are cleared from the body by adhering to mucus in the nose, throat and airways and then get expelled by coughing or swallowing. The Amphibole fibers (long and thin) do not clear as easily and it is therefore thought that they can embed into the lining of the lungs and chest and result in mesothelioma.

Asbestosis (scar tissue in the lungs) or lung cancer can also be caused by the inhalation of asbestos fibers. In fact, people exposed to asbestos are seven times more likely to develop lung cancer over the general public. Workers who sustain high levels of asbestos exposure are more likely to die from asbestosis, lung cancer or mesothelioma than any other disease. It is also believed that the action of coughing up and swallowing asbestos could contribute to a form of mesothelioma originating in the abdomen called peritoneal mesothelioma. Mesothelioma has been found to exist in other organs of the body as well such as the larynx, pancreas and colon, but those instances are extremely limited compared to lung cancer incidents.

The chance of developing mesothelioma is in direct proportion to the duration and amount of asbestos exposure that an individual sustains. Those who are exposed to high levels of asbestos at a young age, for long periods of time have a greater risk of being diagnosed with mesothelioma than those who have short, low level exposure. Another important consideration is that Mesothelioma can take a long time to manifest. Often, twenty to forty years can elapse from the time of exposure to diagnosis. Genetic factors can also play a role which explains why not everyone exposed to asbestos develops and asbestos related disease.

Radiation

Thorium dioxide (Thorotrast), a substance used in x-ray tests in the past has reported links to pleural mesothelioma and peritoneal mesothelioma. The use of Thorotrast has been discontinued for many years due to this discovery.

Zeolite

Some mesothelioma cases in the Anatoli region within Turkey have been linked to Zeolite, a silica based mineral with chemical properties similar to asbestos found in the soil there.

Simian Virus 40 (SV40)

Some scientists have found the simian virus 40 (SV30) in mesothelioma cells from humans and have been able to create mesothelioma in animals with the virus. The relationship between this virus and mesothelioma is still unclear, however, and further research is being conducted to gain clarity on this potential link.

Tobacco

Smoking alone is not linked to mesothelioma, but smokers who are exposed to asbestos have a much higher chance of developing lung cancer (as much as fifty to ninety percent higher). Research indicates that lung cancer is the leading cause of death among asbestos workers.

Source : National Cancer Institute - Fact Sheets: Risk Factors and Possible Causes
http://www.cancer.gov/cancertopics/factsheet/Risk

Cell Types of Mesothelioma

Malignant mesothelioma can also be classified by different cancer cell types, each of which tends to behave differently. There are three classifications assigned to mesothelioma cell types.

Epithelial Mesothelioma is the most common cell type and accounts for approximately 50-75% percent of all diagnosed cases each year. These cells are uniform in shape, with an elongated pattern that makes them easily distinguishable when viewed under high magnification. These cancers are adenocarcinomas, malignancies which are more commonly associated with pure lung cancers as opposed to cancers of the mesothelium.

Sarcomatoid mesothelioma is a less common cell type, accounting for between 7 and 20% of diagnosed cases each year. These cells grow forth out of supportive structures, such as muscles and bones.

Biphasic mesotheliomas are those with a mix of epithelial and sarcomatoid cell types. Treatment options do not vary greatly between cell types, but often sarcomatoid mesotheliomas are more difficult to treat as a result of the surrounding affected tissues from which they spread.

Thoracoscopy and the use of special stains can be helpful in identifying cellular classifications, though obtaining adequate tissue samples often require more invasive surgeries.

Source : Mesothelioma

Malignant Pleural Mesothelioma

Malignant pleural mesothelioma is a cancer of the thin layer of tissue that lines the chest and lungs. It is a rare form of cancer that is mostly associated with exposure to asbestos. Malignant pleural mesothelioma is a fast-moving cancer with a median survival time of between one and two years.
The majority of mesotheliomas are associated with asbestos exposure. Asbestos was used widely in the United States for insulation, and while awareness of its harmful effects is increasing, asbestos can still be found in older buildings. People who work in industries using asbestos in some form, such as insulation manufacturers, insulation workers, and ship builders, may be at increased risk to develop mesotheliomas. The time between exposure and development of a cancer may be decades, which is why it is usually diagnosed in older people. More men than women get this type of cancer. Close contacts of people who have been exposed to asbestos, such as family members, may also be at risk.
Some symptoms of this cancer are increasing breathlessness, pain in the chest or under the ribcage, an abdominal lump or swelling, fever and unexplained weight loss. Imaging tests like a CT scan may show a collection of fluid in the pleural cavity of the chest. Pleural tissue and fluid is also tested to detect cancerous cells and certain chemicals that can rule out a diagnosis of pleural mesothelioma.
Depending on the extent of spread of cancer, malignant pleural mesotheliomas are conventionally treated with some combination of chemotherapy, radiotherapy and surgery to remove as much of the cancer as possible. Aggressive treatment strategies are the norm, though the exact treatment depends on how far the cancer has spread. A number of experimental treatments are currently being evaluated in clinical trials.