Mesothelioma

Mesothelioma is a type of cancer that starts from mesothelial cells. These cells line the outer surface of most of the body’s internal organs, creating a protective layer called the mesothelium. Some mesotheliomas form a mass (tumour), while others grow along the mesothelium and form a thick covering.

It usually takes around 40 years after exposure to asbestos for a person to develop mesothelioma, but it can take anywhere from 10 to 60 years. Mesothelioma is more common in men, who are about 4 times more likely than women to be diagnosed, and it is more common in people over the age of 65.

Types of mesothelioma#

The most common form is pleural mesothelioma, which develops in the mesothelium of the lungs. Although it involves the lining of the lungs, it is not lung cancer and is diagnosed and treated differently. About 95% of mesotheliomas are in the chest.

The second most common form is peritoneal mesothelioma, which develops in the mesothelium that lines the walls and organs of the abdomen and pelvis. Less than 5% of all mesotheliomas are in the abdomen and pelvis.

More rarely, mesothelioma occurs in the pericardium, the lining of the heart (pericardial mesothelioma). Even more rarely, it can occur in the membrane around the testicles (testicular mesothelioma).

Signs and symptoms#

The first signs of mesothelioma are often similar to other conditions, and the symptoms may come and go. It may take some time to be diagnosed, as more common conditions are usually investigated first. Always let your doctor know if you may have been exposed to asbestos in the past, as many doctors will not automatically suspect mesothelioma.

Symptoms of pleural mesothelioma may include:

• pain in the chest, around the ribs or in the shoulder, which may be sharp and stabbing or dull and persistent, and is often made worse by breathing in deeply
• shortness of breath, which usually feels worse with activity or when lying down
• a persistent cough or a change in coughing pattern
• general symptoms such as loss of appetite with weight loss, loss of muscle bulk, fatigue or loss of energy, and night sweats

Symptoms of peritoneal mesothelioma may include:

• abdominal pain
• a swollen abdomen
• poor appetite, nausea and vomiting
• bowel or urinary problems
• night sweats or fever

Not everyone with these symptoms has mesothelioma. If you have any of these symptoms or are worried, always see your doctor.

Risk factors#

The primary risk factor for mesothelioma is exposure to asbestos fibres or asbestos dust. Asbestos was used in many building products in many countries for much of the 20th century.

People at the highest risk are those who may have worked with asbestos, such as:

• asbestos cement manufacturing workers
• asbestos miners
• automotive industry workers
• boilermakers and welders
• builders
• gasfitters and electricians
• insulators
• mechanics and metal-fitters
• plumbers
• steelworkers
• telecommunications technicians
• textile workers
• transport workers

Others at risk include people who cleaned work clothes with asbestos fibres on them, or who spent time in areas where asbestos was disturbed during home renovations or maintenance. While most cases are caused by exposure to asbestos, in some cases there is no clear link.

Diagnosis#

Mesothelioma can be difficult to diagnose, as the symptoms are often the same as those of other health problems and mesothelioma cells can be hard to identify. If you think you have been exposed to asbestos in the past, it is important to tell your doctor.

Tests you may have include:

• blood test
• x-ray
• CT scan
• biopsy
• PET scan

There are other, less common tests that may be used to determine whether you have mesothelioma. Your doctor will discuss these with you.

Staging#

The stage of a cancer describes how far it has grown in the body. Different systems are used for pleural and peritoneal mesothelioma.

The most common system for pleural mesothelioma is the international tumour-node-metastasis (TNM) staging system. Each category is scored, and the higher the number the further the cancer has grown:

• T (tumour) – describes whether the mesothelioma has grown in and beyond the pleural cavity; scored 1 to 4
• N (node) – describes whether it has spread to the lymph nodes; scored 0 to 2
• M (metastasis) – describes whether it has spread to other parts of the body; scored 0 to 1

The most common system for peritoneal mesothelioma is the peritoneal cancer index (PCI). The abdomen and pelvis are divided into 13 regions, and any tumours found are given a score out of 3. The scores for all 13 regions are added together for a maximum of 39. The higher the PCI, the further the cancer has spread.

Prognosis#

Mesothelioma behaves differently in different people. It is often present for many months before being diagnosed at an advanced stage, which affects prognosis. After diagnosis, it may progress quickly or more slowly; if it progresses slowly, some people may live for several years or longer.

When discussing prognosis, your doctor will consider factors such as:

• the type of mesothelioma cell
• the stage and how far it has spread
• the type of treatment you are able to have
• your symptoms, such as weight loss or pain
• your overall health and fitness, and how quickly you recover after procedures
• your blood count – people with normal levels of blood cells usually have a better prognosis

Knowing the stage helps doctors plan treatment but is not always useful for predicting prognosis, partly because it is hard to predict how quickly mesothelioma will grow. In general, the earlier the cancer is diagnosed, the better the outcome. If the cancer has advanced to a point where it is difficult to treat successfully, the priority is to relieve symptoms and improve quality of life.

Treatment#

A range of treatments aim to control the cancer and can include chemotherapy, immunotherapy, radiation therapy or surgery, used alone or in combination. The different types of mesothelioma are treated in different ways. Your specialist will discuss your options, which depend on factors such as the location, stage and type of mesothelioma, your general health and your preferences.

Pleural mesothelioma#

• Chemotherapy – the main chemotherapy drugs are pemetrexed in combination with cisplatin or carboplatin. Research shows this combination can give improved results compared with using a single drug. The goal is usually to shrink the cancer, reduce symptoms and improve quality of life. However, chemotherapy does not work for everyone.
• Immunotherapy – a drug treatment that uses the body’s own immune system to fight cancer. Immunotherapy drugs known as checkpoint inhibitors block proteins that stop immune cells from recognising and destroying cancer cells, so the immune cells can then attack the cancer. It is a relatively new treatment for mesothelioma but is now commonly used.
• Radiation therapy – the use of targeted radiation to kill or damage cancer cells. It may be used as palliative treatment to relieve pain or other symptoms, or after chemotherapy and surgery (adjuvant radiation therapy) to help kill any remaining cancer cells.
• Trimodality therapy – a combination of chemotherapy, radical surgery and radical radiation therapy. The aim is to remove as much mesothelioma as possible and stop remaining cells from growing or spreading. It is an intensive treatment available only in a few specialist centres. Some people continue to live independently afterwards despite reduced lung capacity.

Peritoneal mesothelioma#

For some people whose peritoneal mesothelioma has not spread, an operation called a peritonectomy may be possible. The surgeon removes the parts of the peritoneum where the mesothelioma is growing. The amount removed varies between people, and surgery is usually followed by chemotherapy. Peritonectomy is complex and recovery can take a long time, and only a small number of surgeons perform it.

Chemotherapy may be given as a systemic treatment (into the bloodstream) on its own, or before or after surgery. If you have a peritonectomy, you may have chemotherapy directly into the abdomen. Immunotherapy is similar to that given for pleural mesothelioma, although evidence of how well it works is limited at this time.

Side effects and managing lifestyle changes#

All cancer treatments can have side effects. Your treatment team will discuss these before you start, and you should tell your doctor or nurse about any side effects you experience. Some side effects can be upsetting and difficult, but help is available.

• Fatigue – it is common to feel tired during and after treatment. Cancer-related fatigue is different from ordinary tiredness, as it may not go away with rest or sleep. Sometimes it is caused by a low red blood cell count (anaemia) or the side effects of drugs, and can be treated. While you cannot always get rid of fatigue, you can find ways to improve your energy levels.
• Difficulty sleeping – a good night’s sleep helps maintain energy, reduce fatigue and improve mood. Sleep problems may be caused by pain, breathlessness, anxiety, depression or some medicines. Talk to your doctor about what might help; your medicines may need adjusting.
• Breathlessness – the most common symptom of pleural mesothelioma. It is often caused by a build-up of fluid in the pleural cavity (a pleural effusion), which presses on the lung. In peritoneal mesothelioma, fluid can cause the abdomen to swell, which can be painful and put pressure on the diaphragm. Ask your treatment team about ways to control and drain fluid.
• Pain – the pain caused by mesothelioma itself is usually dull and generalised. If the cancer spreads and presses on bones or organs, it may feel sharp and stabbing. A sharp pain in the chest can also be caused by a blood clot in the lungs, so seek urgent medical attention if the pain is new. Chemotherapy or surgery can injure nerves and cause pain or numbness.

Emotions and wellbeing#

Cancer is a serious disease, treatment can be long and demanding, and there are many periods of waiting and uncertainty. There is no right way to feel, and experiencing a range of emotions is normal. Intense feelings may be constant or come and go; some pass with time while others last longer.

Everyone is different, and you need to deal with the diagnosis in your own way. Your reactions are natural, there are different ways to manage the emotional impact, and support is available.

Having mesothelioma and its treatment can also change the way you feel about yourself, your relationships and sex. These changes can be upsetting and hard to talk about, but doctors and nurses are understanding and can offer support. You can ask for a referral to a counsellor or therapist who specialises in body image, sex and relationships.

Living with advanced cancer#

For many people, mesothelioma is diagnosed at an advanced stage, and the main aim of treatment is to manage symptoms and keep them under control for as long as possible. This is called palliative treatment, and it can improve your quality of life and may help you live longer.

Palliative care is for any stage of advanced cancer, not only for people who are dying, and there are doctors, nurses and others who specialise in it. Palliative treatment may be given alone or with chemotherapy, radiation therapy or immunotherapy. It can help to slow how fast the cancer is growing, shrink the cancer, and help you live more comfortably by managing symptoms such as pain.

Compensation#

Some people who develop mesothelioma due to asbestos exposure may be able to claim compensation. Your legal entitlements depend on where you were exposed, and in some cases the exposure may have occurred in another country. Because mesothelioma takes a long time to develop, the exposure may have happened decades ago, and you might think it was minor or not remember it at all.

It is important to talk to a lawyer or law firm experienced in this area. They can explain what compensation you may be able to claim and help make the process easier to understand.

Support for carers, family and friends#

Caring for someone with cancer can be difficult at times. If you are caring for someone with mesothelioma, support services and cancer nurses are available to help you, the person you care for, and your family and friends.

Key points#

• The main cause of mesothelioma is exposure to asbestos fibres or asbestos dust, and it can develop many years after exposure.
• The most common form is pleural mesothelioma, which develops in the lining of the lungs but is not lung cancer.
• The first signs are often similar to other conditions and may come and go, so diagnosis can take time as more common conditions are investigated first.
• Symptoms of peritoneal mesothelioma may include abdominal pain, swelling, and bowel or urinary problems.
• Not everyone with these symptoms has mesothelioma, but you should always see your doctor if you are worried.

Where to get help#