Causes And Prevention of Mesothelioma Cancer :-
Mesothelioma is most often linked to exposure to asbestos. So much of the research into this disease is based on finding out exactly how asbestos affects the normal cells of the lining of the chest and abdominal cavities. If we can have a better understanding of how asbestos fibres cause cancer and how exposure to this chemical affects us, then we may be able to help prevent the disease. Researchers know that there can be an incredibly long time lag between exposure to asbestos and developing mesothelioma. It can be 40 years or more. This probably meant that it took longer to spot the connection between asbestos and cancer than it otherwise would. But we know now, and the use of asbestos in many countries is now illegal.
Mesothelioma Diagnose :-
Mesothelioma can be very difficult to diagnose. This is because there are many different types of cells that can make up a mesothelioma tumour. Mesothelioma tumour cells are very similar to some types of lung cancer cells. Sometimes it can be very difficult for a pathologist to decide whether or not the cancerous cells are mesothelioma cells, lung cancer cells or even, sarcoma cells.
To help with diagnosis, scientists are trying to find a tumour marker for mesothelioma. A tumour marker is a chemical given off by cancer cells that can be found in the blood and picked up in a blood test. If a definite tumour marker could be discovered for mesothelioma this would be of great benefit for doctors in making more accurate diagnosis of this disease and may also be helpful to monitor the success of treatment.
Research For Mesothelioma Cancer :-
An Australian paper, published in The Lancet in November 2003, is about this search. The researchers were looking into tests for proteins related to mesothelioma. This is early research, but they have had promising results. In their study, 84% of people with mesothelioma tested positive, compared to 2% with other cancers or other lung disease. In a group of people who had been exposed to asbestos but did not have mesothelioma, 7 out of 40 tested positive. 3 of these 7 developed mesothelioma and another got lung cancer within 5 years of the positive test. None of the 33 people who tested negative got mesothelioma within the 8 years following the study. It may be that researchers can build on this work to develop a test for screening for mesothelioma and tests for monitoring the disease in people who already have it.
Chemotherapy :-
It has been a major challenge for doctors to find chemotherapy drugs that work well in treating malignant mesothelioma. Many trials have been done using epirubicin, doxorubicin, cisplatin and methotrexate, but no standard treatment has been set. This has led researchers to look at newer chemotherapy drugs in combination with some already tried. Drugs and combinations in trial include
Gemcitabine and cisplatin
Vinorelbine (Navelbine)
Topotecan
Irinotecan, cisplatin and mitomycin C
Pemetrexed
Raltitrexed (Tomudex)
OnconaseMost studies giving gemcitabine alone have not been successful. A small number of trials using gemcitabine in combination with cisplatin, have produced some promising results. Many doctors now use this combination of drugs to treat malignant mesothelioma. But more trials are needed before it may be considered as standard treatment.
Wednesday, February 20, 2008
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Other Preventions For Mesothelioma Cancer :-
Treating Fluid around the lungs :-
In mesothelioma, fluid can collect inside the chest. This makes it more difficult for your lung to expand and so it is harder to breathe. Doctors call this pleural effusion. It is usual to treat this by drawing off the fluid and 'sticking' the pleura together. Doctors do this by putting in some sort of irritant, usually bcg vaccine, talc or chemotherapy. You can also treat pleural effusion by operating to remove the pleura (a pleurectomy). This is called a pleurectomy. There is a trial that is comparing these two approaches to see which is better. While this trial is open and recruiting patients, it will be listed on our clinical trials database. To find it and other trials, go to the database and choose 'lung - mesothelioma' from the drop down menu of cancer types.
Surgery :-
Major surgery for people with mesothelioma has not always been thought a good idea by surgeons. This is because surgery cannot cure the disease. And because many people with mesothelioma are not fit enough to get through a very large operation. But the point of surgery in mesothelioma is to slow the cancer down, rather than cure it. The operation that can be done to remove mesothelioma is called an extrapleural pneumonectomy (EPP). This means removing the lung and the lining of the chest cavity (the pleura) on the affected side. It may help people to live more comfortably for longer. But this has to be tested because, on the other hand, it could mean that having such major surgery means people die sooner than they would have.
Oncogenes :-
The main focus of gene therapy research for mesothelioma involves injecting a virus that has been modified in the laboratory. The virus is injected into the pleural space in your chest, where mesothelioma develops. The idea is that the virus infects the mesothelioma cells with a gene. The gene makes the cancer sensitive to a specific drug that will kill the mesothelioma cells. Without the virus carrying this gene into the cells, the drug would not usually kill them. Much gene therapy research is still centred on how to get the virus into the cancer cells reliably and it will be a while before we will be able to see whether this will develop into a useful treatment. We don't know of any current mesothelioma gene therapy trials that are open and recruiting patients in the UK.
Anti-angiogenic therapy :-
Angiogenesis means growth of new blood vessels. As they get bigger, cancers need to grow their own blood vessels. Without its own blood supply, a cancer cannot continue to grow. Two of the most important chemicals controlling blood vessel growth are called vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF-2). People with mesothelioma have much higher levels of VEGF than people with any other type of cancer. If the VEGF can be blocked, this could control the growth of blood vessels supplying the mesothelioma tumours. This treatment is a type of biological therapy. These are treatments that use natural body substances (or drugs that block them) to treat cancer. There is more about biological therapies in our cancer treatments section. A drug called bevacizumab is a treatment that stops production of VEGF.
Immunotherapy :-
Immunotherapy is treatment with natural substances that the body uses to fight infection and disease. Immunotherapy works by encouraging the body's natural defence system - the immune system - to attack cancer cells. Immunotherapy is really a type of biological therapy. These are a group of treatments that use natural body substances (or drugs that block them) to treat cancer.
Photodynamic Therapy (PDT) :-
This is a relatively new treatment that is used for a few types of cancers. In PDT, a drug called a photosensitising agent is injected into the bloodstream and absorbed by the body's cells. The drug makes cells sensitive to light. When the area to be treated is exposed to laser light, the cells are killed.
PDT has to be combined with an operation to treat mesothelioma. This has been tried for early stage mesothelioma. The photosensitising drug is injected into your bloodstream a few days before surgery. During surgery, the surgeon then shines the laser light directly onto the pleura.
PDT has been shown to be a safe type of treatment with other types of cancer. But in phase 1 and phase 2 clinical trials for mesothelioma, there were some major complications on a few occasions and so doctors have not widely accepted this treatment. It is particularly likely to be risky when used with major surgery and this combination of treatments is not available in the UK. There are no claims that this treatment will cure anyone of mesothelioma. It is very experimental. We have included it here because it is something you may have read or heard about.
Treating Fluid around the lungs :-
In mesothelioma, fluid can collect inside the chest. This makes it more difficult for your lung to expand and so it is harder to breathe. Doctors call this pleural effusion. It is usual to treat this by drawing off the fluid and 'sticking' the pleura together. Doctors do this by putting in some sort of irritant, usually bcg vaccine, talc or chemotherapy. You can also treat pleural effusion by operating to remove the pleura (a pleurectomy). This is called a pleurectomy. There is a trial that is comparing these two approaches to see which is better. While this trial is open and recruiting patients, it will be listed on our clinical trials database. To find it and other trials, go to the database and choose 'lung - mesothelioma' from the drop down menu of cancer types.
Surgery :-
Major surgery for people with mesothelioma has not always been thought a good idea by surgeons. This is because surgery cannot cure the disease. And because many people with mesothelioma are not fit enough to get through a very large operation. But the point of surgery in mesothelioma is to slow the cancer down, rather than cure it. The operation that can be done to remove mesothelioma is called an extrapleural pneumonectomy (EPP). This means removing the lung and the lining of the chest cavity (the pleura) on the affected side. It may help people to live more comfortably for longer. But this has to be tested because, on the other hand, it could mean that having such major surgery means people die sooner than they would have.
Oncogenes :-
The main focus of gene therapy research for mesothelioma involves injecting a virus that has been modified in the laboratory. The virus is injected into the pleural space in your chest, where mesothelioma develops. The idea is that the virus infects the mesothelioma cells with a gene. The gene makes the cancer sensitive to a specific drug that will kill the mesothelioma cells. Without the virus carrying this gene into the cells, the drug would not usually kill them. Much gene therapy research is still centred on how to get the virus into the cancer cells reliably and it will be a while before we will be able to see whether this will develop into a useful treatment. We don't know of any current mesothelioma gene therapy trials that are open and recruiting patients in the UK.
Anti-angiogenic therapy :-
Angiogenesis means growth of new blood vessels. As they get bigger, cancers need to grow their own blood vessels. Without its own blood supply, a cancer cannot continue to grow. Two of the most important chemicals controlling blood vessel growth are called vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (FGF-2). People with mesothelioma have much higher levels of VEGF than people with any other type of cancer. If the VEGF can be blocked, this could control the growth of blood vessels supplying the mesothelioma tumours. This treatment is a type of biological therapy. These are treatments that use natural body substances (or drugs that block them) to treat cancer. There is more about biological therapies in our cancer treatments section. A drug called bevacizumab is a treatment that stops production of VEGF.
Immunotherapy :-
Immunotherapy is treatment with natural substances that the body uses to fight infection and disease. Immunotherapy works by encouraging the body's natural defence system - the immune system - to attack cancer cells. Immunotherapy is really a type of biological therapy. These are a group of treatments that use natural body substances (or drugs that block them) to treat cancer.
Photodynamic Therapy (PDT) :-
This is a relatively new treatment that is used for a few types of cancers. In PDT, a drug called a photosensitising agent is injected into the bloodstream and absorbed by the body's cells. The drug makes cells sensitive to light. When the area to be treated is exposed to laser light, the cells are killed.
PDT has to be combined with an operation to treat mesothelioma. This has been tried for early stage mesothelioma. The photosensitising drug is injected into your bloodstream a few days before surgery. During surgery, the surgeon then shines the laser light directly onto the pleura.
PDT has been shown to be a safe type of treatment with other types of cancer. But in phase 1 and phase 2 clinical trials for mesothelioma, there were some major complications on a few occasions and so doctors have not widely accepted this treatment. It is particularly likely to be risky when used with major surgery and this combination of treatments is not available in the UK. There are no claims that this treatment will cure anyone of mesothelioma. It is very experimental. We have included it here because it is something you may have read or heard about.