Mesothelioma

What is it?

Mesothelioma , or more precisely, malignant mesothelioma, is a form of cancer which can affect the lungs (pleura mesothelioma) and the abdomen (peritoneal mesothelioma). It is a rare form of cancer. However, it is becoming more common.

The mesothelium is a protective covering of both the lung and abdomen, which comprises of two protective layers with a gap in between. It is in this gap that cancerous cells can develop and grow out of control, and it is this which we call mesothelioma. It usually remains in the protective space in the protective sack. However, it has been to known to migrate (metastasize) to other parts of the body, but this is rare. However, as the heart is located next to the lungs, it leaves the heart somewhat vulnerable to exposure to mesothelioma, and can sometimes be affected too. But this is rare.

Most people who do contract the disease are diagnosed with the form of cancer that affects the lungs - pleural mesothelioma. Abdominal mesothelioma is significantly less common.

Types of Mesothelioma

There are two types of mesothelioma - pleural mesothelioma, which affects the lungs, and peritoneal mesothelioma which affects the abdomen. Pleural mesothelioma develops in the tissue lining covering the lungs, whereas Peritoneal Mesothelioma develops in the lining surrounding the abdomen. This form of mesothelioma is rare compared to pleural mesothelioma.

A close look at pleural mesothelioma will reveal that the cells can be grouped into three different types, namely Epithelioid, Sarcomatoid or fibrous, and a mixed type, also known as Biphasic. These cells can be divided further into types called tubopapillary cell, acinar cell and small cell.

Causes Of Mesothelioma

It has been found that the primary cause of mesothelioma is an exposure to asbestos or breathing in glass particles. 70-80% of people who have contracted mesothelioma have been exposed to asbestos at some point in their life. However, there are also those who have apparently never had heavy or prolonged exposure to asbestos in their lives. These cases account for around 20-30% of cases.

Men seem to be more at risk than women, but this could be due to the greater numbers of men who have been exposed to asbestos in their working lives. Asbestos is in fact to be found in many materials. It was much more likely that cases of mesothelioma were inadvertently born by being exposed to asbestos many years ago, as the dangers were not known so widely previous to more recent research. It can even effect people like racing drivers who used to wear suits made with asbestos. One such case was the film star Steve McQueen who enjoyed racing whenever he could. He may have contracted mesothelioma this way. He may also have contracted the disease from his time serving in the U.S. Marines on warships which had pipes insulated I asbestos. He did succumb to mesothelioma however after many years of racing. It is thought this was probably the most likely cause of his death. Cases of mesothelioma are now becoming far more common, especially in men. This is probably due to the fact that men were exposed to asbestos in work situations, that are only now coming to light. And this is where it is difficult to detect mesothelioma early on. It is hardly detectable for many years, by which time it is really too often too late to treat effectively.

Aside from the exposure to asbestos in the environment, there are other risks of contracting mesothelioma. Exposure to asbestos makes you more prone to contracting mesothelioma. The virus called SV40 would make you more vulnerable to contracting mesothelioma. One other risk factor that would make you vulnerable to mesothelioma is if you lived in parts of Turkey where the mineral Zeolite is to be found.

Research has pointed to a possible link with the simian virus 40 or SV40, which may well be acting as a cofactor I contracting Mesothelioma. There are other possible factors which include the inhalation of fibrous silicates including erionite, intrapleural thorium dioxide or Thorotrast and irradiation. But these are rare occurrences.

Statistics - Prognosis, Mortality & Survival

A total of 27.5 million people were diagnosed as suffering form mesothelioma in the United States from 1940 to 1979. However, the incidence of pleural mesothelioma within the male Caucasian population in the U.S. shot up to 2,000 per annum to 3,000. However, again, because the symptoms of mesothelioma are difficult to discern from other complaints, these figures may be inaccurate or distorted.

Statistics can be useful to an extent. However, they only serve to indicate general patterns. Each case is different and people react differently to different forms of cancer treatments. Cancer cells grow at different rates in different patients. Some patients have better chances of survival than others. Genes and environment for instance can also affect a person’s prognosis.

Because mesothelioma is not easily detectable until usually the late stages, when it is advanced, doctors will normally give a 1 year + prognosis for surviving mesothelioma in both forms. However, there are also cases that have outlived such predictions.

Surgical removal of mesothelioma gives a better chance of survival, but not all patients can have surgery. There is evidence that post surgery treatment using chemotherapy, radiotherapy or biological therapies, can increase survival by a few weeks.

General rates of survival record a 40% survival rate beyond the first year of diagnosis. Around 20% of patients tend to survive beyond year 2, 10% survive beyond year 3 and 8% beyond year 5. For those patients who have benefited from early diagnosis and treatment, the survival rate is around 50% for surviving beyond year 2.

The type of mesothelioma will affect chances and rates of survival. Desmoplastic and sarcomatous forms have been found to be difficult to treat, and therefore survival rates have been poor. Whereas people with epithelial type mesothelioma, not the mixed type, have shown to have a far better chance of survival.

A patient’s ‘Performance Status’ (PS) or general health is also a factor in the survival statistics. A person who is assessed as having a PS of ‘0’ is thought to be completely able to support him or herself. Whereas a score of 1 denotes a person who can do most things well. A higher score denotes a person who is less able to support themselves, and may be more vulnerable to mesothelioma and indeed its treatment. Better rates of survival are expected in patients who have normal levels of white blood cells and haemoglobin.

Statistics do change, and by their nature they are retrospective. They do not take into account he change in methods and new treatments. So they should be viewed as no absolute with regard to any one patient. Statistics show that people’s survival rates are higher if they are treated at a specialist centre, for instance where clinical trials are taking place. In such situations, there is close monitoring and more regular tests are carried out on patients. This obviously affects survival rates with a more positive outcome.

Environmental Risks

Asbestos has been used widely in the building industry. Many farm barns throughout the latter half of the 20th century were constructed with asbestos roofs and walls. It has been widely used in the construction, heating, ship building and mining industries, especially since the Second World War.

A total ban on the use of Asbestos was implemented in 1999. However, buildings that were built or renovated prior to this date may have asbestos materials as part of their construction. It is therefore very important that if asbestos is found in a building tha tit is dealt with properly. This usually means the local council or local government is will require the safe removal of asbestos and it should not be done by you personally. It is a highly dangerous substance and should be removed by specialist services.

Naturally occurring forms of asbestos do occur in the environment however, notably in central Cappadocia, Turkey, where a substance called erionite - a zeolite mineral, which has similar properties to asbestos, and is responsible for the premature death of a significant part of the population in the area where this mineral is found. Research has shown that certain of the population does have a vulnerable predisposition to mesothelioma.

Asbestos has also been widely used in many industrial products produced since the 20th century. Such products include automotive gaskets, textiles, floors, roof shingles, brake linings, building insulation and cement.

Perhaps because the symptoms are not apparent until much later on in life, people who have contracted mesothelioma have died often many years later, often 20 to 50 years after working in an asbestos contaminated area. High death rates have been recorded in areas where asbestos mining has occurred, such as Western Australia for instance. However, the risk is also brought into the domestic places since people who have or do work in asbestos contaminated areas run the risk of infecting their family, since the asbestos fibres or dust can be introduced in to the family home from traces left in the hair and on their clothes. This is why modern practice is for such workers to take showers and change their clothes at the end of their shift prior to going home.

Received wisdom says that there is probably not a safe or minimum level of exposure to asbestos. Therefore any exposure to asbestos may indeed carry a risk of contracting mesothelioma.

Mesothelioma Symptoms

Mesothelioma is not easy to detect, therefore there is no effective screening for mesothelioma at this time, although tests and trials continue. However, even though there are no clear cut definitive signs of mesothelioma, one should be wary if the following symptoms are experienced:-

Peritoneal Mesothelioma

• Abdominal swelling accompanied by pain resulting from fluid build-up in the abdominal cavity - ascites.
• Weight loss or cachexia
• Blood clotting
• Bowel obstruction
• Anmeia
• Fever
• Swelling of the face or neck (problems swallowing) can occur if the cancer has spread beyond the immediate vicinity of the abdomen.

Pleural Mesothelioma

• Pain in the chest due to fluid accumulation in the pleural space, known as pleural effusion.
• Coughing
• Short of breath
• Pain in chest wall
• Anemia or fatigue
• Short of breath
• Fluid surrounding the lung or pleural effusion
• Blood coughed up in the fluid or sputum
• Cough
• Hoarse voice
• Wheezing

Although these are often signs of mesothelioma, they could also be signs of conditions which are less serious. It is possible in extreme cases that the patient may suffer from a collapsed lung as a result of tumour masses.

In addition to the above, the following symptoms maybe a sign of tumours that have developed to a late stage:-

• Weight loss
• Bowel function problems
• An abdominal mass
• Bowel function problems
• Abdominal pain

The following signs may be present in sever cases:-

• Blood sugar level low
• Severe ascites
• Pleural effusion
• Jaundice (a yellow discolouration of the skin and around the eyes)
• Blood clots in veins
• Organ bleeding (disseminated intravascular coagulation)
• Blood clots in the lung arteries, or pulmonary emboli

Staging

Staging is a term used to denote the relative stages of a disease. There are few stages commonly acknowledged due to the rarity of detecting early signs of mesothelioma

However, some sort of staging has been categorized I the U.S. and this is based on the TNM classification, devised by the International Mesothelioma Interest Group. Mesothelioma is staged 1a-IV or one-A to four.

Screening

Unlike many other diseases, screening is not particularly successful for cases of mesothelioma due to the difficulty in detecting it and the fact the symptoms are similar to other conditions. However, one test used in screening is where the level of serum osteopontin is measured, which it is thought might offer some sort of measurable analysis. The affirmed cases appear to have a higher level of soluble mesothelin related protein in around 75% of cases. Doctors have also recently begun to test the Mesomark assay, the substance which measures solublemesothelin related protein levels (SMRPs) which is a function of diseased cells of mesothelioma.

Diagnostic Tests, Treatments & Prognosis

An examination by a GP will be the first port of call. The doctor will determine your general state of health in relation to age, followed by an examination looking for any sign of a lump in any area which may be tender or swollen. The doctor will listen to your chest to determine if there are any signs of fluid accumulation. A referral may then be made to a specialist or a hospital where tests and perhaps X-Rays are carried out. The patient’s medical history is taken into account and blood tests may be taken. As mesothelioma is difficult to detect, a range of tests may be carried out, including several blood tests, a CT or CAT scan or MRI, X-Rays and a laparoscopy or thoracoscopy and biopsy may be taken. Fluid may also be taken from the abdominal region, or around the lungs.

With mesothelioma a build up of fluid is usual, caused by the cancer cells expanding. This is the swelling often found. The fluid may therefore contain cancer cells. Fluid around the lungs is called a pleural effusion, whereas it is called a peritoneal effusion if found around the abdomen and can make the patient feel uncomfortable due to the painful swelling. Whereas any such fluid around the lungs makes breathing difficult.

Some of this fluid is drawn-off and sent to a laboratory where it is tested for cancer cells. Drawing fluid from the chest is called pleural aspiration or thoracocentesis. Drawing fluid from the abdomen is called a peritoneal aspiration or abdoparacentesis. Cancer may be detected using cytopathology. However this is no sure way to determine the presence of mesothelioma. Even an expert practitioner has difficulty detecting the disease using such methods. The most thorough way to determine whether there is a positive trace of it is to do a biopsy. A pathologist performs the operation using a microscope. In performing a thoracoscopy on the chest, a small incision is made and the thin device which has a illuminated end is inserted into the chest between two ribs, in order to perform the operation. Another procedure is to open up the chest completely.

A similar operation is performed on the abdomen if this is where the problem seems to be. In this case a laparoscopy is performed. The idea is to get sufficient material to perform tests on. Sometimes the operation is repeated, sometimes extensively. The biopsy will determine the presence or otherwise of malignant mesothelioma, No one test amongst a variety of available tests is ideal for such determining whether the form of mesothelioma a patient has is benign or malignant. The three histological variants of malignant mesothelioma include Epithelioid, Sarcomatoid and Biphasic or mixed. However it is the Epithelioid which accounts for over half the cases of malignant mesothelioma and holds the promise of a more successful prognosis.

Mesothelioma Video

Below is a must see documentary that is for anyone who has been affected by asbestos or mesothelioma. The documentary explains how a huge number of employees are suffering from asbestos poisoning, mesothelioma and various other asbestos related illnesses due to large companies and corporations. By watching the video you can discover what you can do the protect the rights of workers that are being affected from this terrible disease. Watch the History Of Asbestos by clicking on the video player, courtesy of Free Documentaries and watch free movies.

Surgery Plus Chemotherapy

Whilst success rates of survival are relative to what is a difficult disease to deal with in staving off what is usually a 12 month survival rate, the greatest success have been shown to work when a number of treatments are taken together, such as surgery, radiotherapy and chemotherapy. The most common practice is to embark on pleurectomy/decortication surgery where the chest lining is removed, along with the pericardium and the hemi-diaphragm. Where possible, in consideration of the patient’s ability to cope with radiation therapy, the whole of the hemi-thorax is exposed to radio therapy , post surgery, usually in conjunction with chemotherapy. This is standard practice now thanks to the Boston based pioneering thoracic oncology team at Brigham & Women's Hospital. Extensions to life have been seen reaching beyond 5 years. Survival has been shown not to be achievable using radiotherapy on its own, but significantly more successfully used as a complimentary treatment post op in order to destroy what little cancer cells there may remain when surgery has taken most of the diseased tissue away.

Symptoms due to growth of a tumour such as the obstruction of major blood vessel, is often given palliative treatment.

Chemotherapy has been proven to significantly improve survival rates. In fact it is the only method known to be effective in prolonging survival, from 10 months to over 13 months according to some studies. Cases where a folate supplementation was used, along with B12 have shown the greatest response, while also significantly reducing side effects when 500mcg was administered to the patient, along with intramuscular vitamin B12 of 1000mcg for every 9 weeks. So far, this combined therapy has seen the best response rates with figures of 50 % more remission rates being achieved. Nausea and vomiting are common side effects when radiation is given. There has been evidence of multimodal therapy resulting in a prolonged survival rate of between 3 to 14 years, but this is uncommon.

What remains unanswered is the optimal treatment times using chemotherapy, such as when to commence treatment and the optimal chemotherapy cycles to administer.

Immunotherapy

There are no positive results arising from this area. However, improved reduction of tumour mass by more than 50% has been noted with the use of the drug Interferon alpha.

Heated Intraoperative Intraperitoneal Chemotherapy

This technique has had superior results as effective localisation of treatment in combination with heating the chemotherapy drug has shown to be more effective in chemical absorption into the tissue, with the heat treatment helping to kill the cancer cells whilst leaving the normal healthy cells unaffected. The tumour however - as previously pointed out, should be surgical removed as much as possible prior to such chemical treatment. Heating is maintained at around 40 to 48 degrees and the chemotherapy agent kept in the abdomen for between one to two hours. It can also be used in cases of pleural mesothelioma. Underlying these multimodal treatments however, is the fact that reducing the body mass of the diseased tissue is key to prolonged survival. The additional complimentary treatments such as chemotherapy have a much better chance of being effective when combined with this basic factor of using cytoreductive surgery.

Palliative care can go a long way to offer quality of life to a patient, and in most cases, this is more important for the patient, especially as life expectancy is not favourable or short-lived once an affirmative diagnosis of mesothelioma is made. What are seen as ‘alternative’ forms of treatment such as massage, acupuncture, aromatherapy and reflexology, or indeed any form of stress relieving treatment, can be very helpful in complimenting the palliative approach, and easing the trauma of surgery and the multimodal approach.