All cancer treatments have to be fully researched before they can be used for everyone. This is so we can be sure that:
- they work
- they work better than the treatments already available
- they are known to be safe
The latest research into causes, prevention and treatment for mesothelioma is outlined below.
Causes and prevention
Many cases of mesothelioma are caused by exposure to asbestos.
The MALCS study confirmed that people who worked in jobs with high levels of exposure to asbestos have an increased lifetime risk of developing mesothelioma or lung cancer. The researchers also found an increased risk in men and women who lived with an exposed worker before the age of 30.
Another study, called the TIPS study, aimed to find out if people in the UK are still being exposed to asbestos. It looked for fibres of asbestos in lung tissue samples from people who’ve had surgery for a collapsed lung (pneumothorax).
Mesothelioma can be very difficult to diagnose.
Different cell types
Many different types of cells can develop into a mesothelioma tumour. Tumor cells for mesothelioma are very similar to some types of lung cancer cells. This can make it difficult to decide whether the cancerous cells are mesothelioma cells, lung cancer cells or even sarcoma cells.
To help with diagnosis, scientists are trying to find out whether mesothelioma cells give off particular chemicals that can be shown in a blood test. These chemicals are called tumour markers. They can also help in monitoring how well treatment is working.
Tumour markers are still being researched and are not routinely available to patients. There is potential for combining them to improve their effectiveness.
SMRP and osteopontin
The tumour markers soluble mesothelin related protein (SMRP) and osteopontin are being researched.
SMRP and osteopontin levels are raised in many people with mesothelioma. But SMRP levels are also raised in people with ovarian cancer. So SMRP can be useful in finding mesothelioma and ovarian cancer, but it does not help to distinguish between them.
Recent studies suggest that SMRP levels at diagnosis may help to give an idea of prognosis or how well your treatment is working. But more studies are needed to look at this.
CA 125 and CA 15-3
Useful tumour markers for diagnosing and monitoring mesothelioma in the abdomen are CA 125 and CA 15-3. Research is looking at how helpful these may be.
There is some evidence that your genetic make up could affect your risk of mesothelioma. As well as asbestos, exposure to a mineral called erionite, is a risk factor.
Researchers in Turkey found that:
- all members of some families exposed to erionite developed mesothelioma
- no members of other families exposed to erionite developed it
They think that the families affected must have a gene that increases their risk. This could also explain why some people who are exposed to asbestos do not develop mesothelioma, while others do.
We need more research before we can know that specific gene changes increase your risk of mesothelioma.
Genes and treatment
Understanding changes in the genes of the mesothelioma cells helps in developing treatments. They aim to understand:
- more about how mesothelioma develops
- how gene changes in cancer cells affect how well different treatments work
Several gene mutations have been identified and found in patients with mesothelioma. These include NF2 and BAP-1.
Gene mutation testing is not performed routinely in mesothelioma. It may sometimes be performed as part of a clinical trial.
Finding chemotherapy drugs that can treat mesothelioma has been a challenge for researchers. Many trials have been done.
The most commonly used combination of chemotherapy drugs for mesothelioma in the chest is currently pemetrexed and cisplatin or raltitrexed and cisplatin. Sometimes pemetrexed is combined with carboplatin. Other drugs being looked at in trials include:
- raltitrexed (Tomudex)
- gemcitabine – usually in combination with cisplatin
- vinflunine (Javlor)
A trial called MS-01 compared the following treatments:
- active symptom control (ASC)
- ASC and vinorelbine
- ASC, mitomycin, vinblastine and cisplatin (MVP)
The trial found that:
- the chemotherapy drug combination MVP is no better than active symptom control
- vinorelbine on its own may control symptoms better and could potentially help people to live longer
More research is needed.
Another trial looked at a combination of the drugs irinotecan, cisplatin and mitomycin (called IPM). The results were encouraging but more research is needed.
Onconase (ranpirnase) is an experimental chemotherapy drug made from leopard frog eggs. It is not available in the UK. We've included it here because you may see it mentioned online.
A phase 3 clinical trial has been going on in the USA and Germany comparing onconase and doxorubicin with doxorubicin alone for people with mesothelioma. The results seem to show that adding onconase to doxorubicin helped some people to live longer. Studies may now also look at combining onconase with other treatments.
Cisplatin and pemetrexed is the most common combination of chemotherapy drugs given into a vein for peritoneal mesothelioma.
But other drugs are being tested, including:
Doctors are also using chemotherapy into the abdomen after surgery to try to control peritoneal mesothelioma.
Topotecan and irinotecan have not worked well at controlling mesothelioma when given by themselves. But in combination with other drugs, there have been some good results.
Advances have been made in surgery for mesothelioma in recent years.
Few people with mesothelioma are fit enough to get through a very large operation. But some people can live longer after surgery to remove the pleural tumour on the affected side (either pleurectomy, decortication or extrapleural pneumonectomy), followed by chemotherapy or radiotherapy.
Research is continuing to look into this intensive treatment because there is a risk of dying during such major surgery.
The MARS trial looked at the benefits and risks of extrapleural pneumonectomy (EPP) for people with mesothelioma who had also had chemotherapy treatment.
The trial found that EPP did not help most people live longer. Many people also had poorer quality of life after this surgery.
The MARS2 trial compares surgery and chemotherapy with chemotherapy alone for people with mesothelioma affecting one side of their chest.
Mesothelioma can sometimes cause fluid to collect between the 2 layers of the pleura (pleural space). Doctors call this fluid collection a pleural effusion. The pleura is a membrane that covers your lungs. It makes fluid that helps them move when you breathe.
Usually a pleural effusion is treated by draining off the fluid and 'sticking' the layers together. Doctors do this by putting in an irritant, usually BCG vaccine, sterile talc or chemotherapy. This is called pleurodesis.
The MesoVATS trial compared talc pleurodesis with an operation to remove part of the membrane around the lungs. This operation is called video assisted thorascopic partial pleurectomy (VAT-PP).
The TIME3 trial is looking at using a drug called urokinase to help drain fluid from around the lung to make breathing easier. Sometimes there is more than 1 pocket of fluid between the lung and chest wall. This makes it difficult to drain all the fluid away. Urokinase may help to break down the pockets.
The OPTIMUM trial is looking at 2 ways to treat fluid around the lung. The researchers are comparing a chest drain and pleurodesis with an indwelling pleural catheter (IPC) and pleurodesis. An IPC is a small tube that is put under the skin and into the pleural space.
Some people with mesothelioma have radiotherapy to the part of their chest where they had tissue samples taken (biopsies) through the skin of the chest or fluid drained from the chest.
This aims to stop mesothelioma cells growing in scar tissue. Doctors do this as soon after the procedure as possible. But some recent studies have shown that this may not reduce the chances of mesothelioma spreading to the chest wall.
The PIT trial looks at whether treating the wound from your mesothelioma tests with radiotherapy helps to prevent or delay small cancer growths (nodules) developing in that area. This trial has now closed and we are waiting for the results.
The SMART trial is looking at the best time to give radiotherapy to prevent mesothelioma spreading after a procedure to the chest wall. It also looks at how giving radiotherapy soon after a procedure affects quality of life, and at its side effects.
This trial has now closed and we are waiting for the results.
Intensity Modulated Radiotherapy (IMRT)
There is a newer type of radiotherapy called Intensity Modulated Radiotherapy (IMRT). The radiotherapy beams can be shaped more accurately and so may avoid more of the surrounding normal tissue. So you may have fewer side effects.
Biological therapies are drug treatments that interfere with the way cells work. They can be used to:
- boost the body's immune system so it can fight off or destroy cancer cells (immunotherapy)
- block the signals that tell cells to grow
Various biological therapy drugs are being tried for mesothelioma.
The MAPS trial
The MAPS trial looked at a first treatment for advanced pleural mesothelioma. It added the biological therapy drug bevacizumab (Avastin) to the standard chemotherapy treatment (cisplatin plus pemetrexed).
The trial found that people survived about 2 months longer when bevacizumab was added to the chemotherapy.
The researchers recommend bevacizumab as a treatment alongside chemotherapy for people with pleural mesothelioma.
Current biological therapy trials
A new drug called Arenegyr (NGR-hTNF) has been tested in people who have already had chemotherapy for mesothelioma. In early trials the drug seemed to control the mesothelioma for a few months and increase survival rates. This drug will now be tested in phase 3 trials to see how well it works.
Bortezomib (Velcade) is being used in trials on its own and in combination with cisplatin.
Cetuximab is being looked at in a phase 2 trial in combination with pemetrexed and cisplatin.
The COMMAND trial is looking at a new drug called defactinib to treat pleural mesothelioma. This trial has now closed and we are waiting for the results.
By studying how changes in genes make normal cells become cancerous, scientists aim to eventually develop gene therapy. This would replace damaged genes in the cancer cells with normal cells.
One type of gene therapy research for mesothelioma looks at 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 drug that will kill the mesothelioma cells.
There is a trial looking at a virus called HSV1716, which infects cancer cells and kills them.
Researchers in Europe and the US are looking at developing a vaccination to treat mesothelioma.
There are cells in your blood called dendritic cells. They help other cells in the immune system recognise cells that are foreign to the body, such as bacteria and viruses.
The researchers hope that altering genes inside your dendritic cells will make immune system cells (called T cells) recognise mesothelioma cells as foreign.
The SKOPOS trial is looking at a different type of cancer vaccine called TroVax.
In photodynamic therapy (PDT) a drug called a photosensitising agent is injected into your bloodstream, and absorbed by your body's cells. The drug makes cells sensitive to light. Cancer cells absorb more of the drug than normal cells. So when the area to be treated is exposed to laser light, the cells are killed.
To treat mesothelioma, PDT has to be combined with an operation. This has been tried for early stage mesothelioma. The drug is injected into your bloodstream a few days before surgery. The surgeon then shines the laser light directly onto the pleura during surgery.
In phase 1 and phase 2 clinical trials for mesothelioma there were some major complications on a few occasions. So doctors have not widely accepted this treatment. It is particularly likely to be risky when used with major surgery – this combination of treatments is not available in the UK.
There are no claims that this treatment will cure anyone with mesothelioma. It is very experimental. We include it here because it is something you may have read or heard about.
People living with mesothelioma may have physical and psychological symptoms that affect their quality of life. Palliative care involves caring for your physical, emotional, psychological and spiritual needs.
The RESPECT-Meso study aims to see if giving specialist palliative care early in mesothelioma treatment can:
- improve your quality of life and wellbeing throughout the course of your illness
- improve the wellbeing of family or close friends