What is 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, forming a protective membrane called the mesothelium.
Some mesotheliomas form a mass (tumour), while others grow along the mesothelium and form a thick covering. In later stages, mesothelioma may spread (metastasise) to other parts of the body.
The mesothelium that covers the lungs is called the pleura. Mesothelioma that develops in the pleura is known as malignant pleural mesothelioma or, simply, pleural mesothelioma. It accounts for more than 90% of all mesotheliomas.
Although pleural mesothelioma involves the lining of the lungs, it is not lung cancer and is diagnosed and treated differently.
There are two layers in the pleura. The inner layer lines the surface of the lungs and is called the visceral pleura. The outer layer lines the chest wall and the diaphragm, and is called the parietal pleura.
Between the two layers is the pleural cavity (also called the pleural space), which normally contains a small amount of fluid. This fluid allows the two layers of pleura to slide over each other so the lungs move smoothly against the chest wall when you breathe. When mesothelioma develops in the pleura, the delicate layers of the pleura thicken and may press on the lung, preventing it from expanding when breathing in (inhaling). Excess fluid often collects between the two layers – this is called a pleural effusion.
The mesothelium that lines the walls and organs of the abdomen and pelvis is called the peritoneum. Mesothelioma that develops in the peritoneum is known as malignant peritoneal mesothelioma or, simply, peritoneal mesothelioma. It accounts for less than 10% of all mesotheliomas.
The peritoneum has two layers. The inner layer lines the surface of organs such as the bowel, liver and ovaries and is called the visceral peritoneum. The outer layer lines the walls of the abdomen and pelvis, and is called the parietal peritoneum.
Between the two layers is the peritoneal cavity, which normally contains a small amount of fluid. This fluid allows the two layers to slide over each other as you move around. In people with peritoneal mesothelioma, excess fluid often collects between the two layers – this is known as ascites or peritoneal effusion.
Rarely, mesothelioma occurs in the pericardium, the mesothelium covering the heart. This is called pericardial mesothelioma. Even more rarely, mesothelioma can occur in the membrane around the testicles, the tunica vaginalis. This is called testicular mesothelioma.
The pleura and the peritoneum
This section discusses pleural mesothelioma (lungs) and peritoneal mesothelioma (abdomen and pelvis). It is rare for mesothelioma to start in more than one area of the body.
The respiratory system
Pleural mesothelioma affects the pleura, the membrane that covers the lungs. The lungs are the main organs for breathing and are part of the respiratory system, along with the nose, mouth, windpipe (trachea), large airways (bronchi) and smaller airways (bronchioles). The lungs rest on the diaphragm, which is a wide, thin muscle that helps with breathing.
The abdomen and pelvis
Peritoneal mesothelioma affects the peritoneum, the membrane that lines the walls and covers the organs of the abdomen and pelvis. These organs include the stomach, bowel, liver, kidneys and, in women, the uterus and ovaries.
What causes mesothelioma?
Exposure to asbestos is the main cause of mesothelioma. Very rarely, mesothelioma has been linked with previous radiotherapy to the chest.
Asbestos is the name of a group of naturally occurring minerals that are resistant to high temperatures and humidity. It was used in many building products in Australia from the 1940s until 1987. Since 2004, Australia has had a ban on asbestos being sold, reused and/or imported. It is still present in many older buildings, so special precautions must be taken when renovating or demolishing. It has also been found in some recently imported products despite the ban.
People most likely to have been exposed to asbestos at work include asbestos miners and millers, asbestos cement manufacturing workers, laggers and insulators, builders, plumbers and electricians, automotive industry workers, mechanics, transport workers (especially waterside workers), and textile workers. People who haven't worked directly with asbestos but have been exposed to it can also develop mesothelioma. These can include people cleaning work clothes with asbestos fibres on them or people disturbing asbestos during home renovations or maintenance.
It can take many years for mesothelioma to develop after a person is exposed to asbestos. This is called the latency period or interval – it is usually between 20 and 60 years (most commonly around 40 years) after exposure.
Can I seek compensation?
People who develop mesothelioma due to asbestos exposure may be able to claim compensation. Start making notes and talking to family and friends about when you may have been exposed to asbestos. It is important to get advice from an experienced lawyer as soon as possible after diagnosis. Read more about seeking compensation.
How common is mesothelioma?
Australia has one of the highest rates of mesothelioma in the world, with 732 Australians diagnosed in 2014. Of these, more than 93% had pleural mesothelioma, about 6% had peritoneal mesothelioma, and about 1% had a rarer type. 2
Men are over three times more likely than women to be diagnosed with mesothelioma, probably because many cases have been caused by exposure to asbestos at work. Western Australia has the most cases per population due to past asbestos mining. Mesothelioma is more common in people over the age of 65, but can occur in younger people.
The Australian Mesothelioma Registry monitors new cases of mesothelioma and collects information about asbestos exposure to help reduce mesothelioma in the future. Health professionals may tell the registry about new cases, or you can self-notify by visiting mesothelioma-australia.com or calling 1800 378 861.
What are the symptoms?
The first signs of mesothelioma are often vague and similar to other conditions. If you are concerned, see your general practitioner (GP). It may take some time to be diagnosed, as the symptoms may come and go, and more common conditions are likely to be investigated first. Let your GP know if you may have been exposed to asbestos in the past.
Symptoms will depend on where the mesothelioma has developed. Pleural mesothelioma may cause:
Shortness of breath (breathlessness)
This common symptom usually feels worse with activity or when you are lying down. It is often caused by a build-up of fluid in the chest called pleural effusion (see draining fluid).
This can occur in the chest around the ribs or in the shoulder. It may be sharp and stabbing, made worse by breathing in deeply, or dull and persistent. You may also have a change in skin sensation or sensitivity to touch.
Other general symptoms
Some people experience loss of appetite with weight loss, loss of muscle bulk, loss of energy, a persistent cough or a change in coughing pattern. Some people also experience night sweats.
Peritoneal mesothelioma may cause: abdominal pain; a swollen abdomen; poor appetite, nausea and vomiting; night sweats or fever; and bowel or urinary problems.
What can I expect after diagnosis?
You are likely to feel shocked and upset when told you may have mesothelioma. It's common to have many questions and concerns about what the diagnosis will mean for you.
You will have various tests to confirm that you have mesothelioma and work out how far it has progressed. The results will allow you and your health professionals to make decisions about the best approach to treatment.
Mesothelioma is often diagnosed at an advanced stage. For most people, the main goal of treatment is to manage symptoms and improve quality of life.
Depending on how advanced the mesothelioma is and other factors, you may be offered active cancer treatments to achieve a longer period of disease control and improve quality of life.
Depending on the impact of mesothelioma on your health, you may experience periods of relatively good health when symptoms are under control or less active. You may also experience periods when symptoms need more intensive treatment. See information about living with mesothelioma. For questions you may want to ask your doctor, see our questions checklist.
Which health professionals will I see?
If you have mesothelioma, you will be cared for by a range of health professionals who specialise in different aspects of your treatment. This is known as a multidisciplinary team (MDT) and may include some or all of the health professionals described in the table below.
Some people are diagnosed and treated in specialist centres in major cities around Australia. To find out if there is a specialist unit near you, ask your doctor or call Cancer Council 13 11 20. If you live in a rural or regional area, or find it difficult to travel far, your GP can provide care and discuss further options with an MDT from a specialist centre.
|MDT health professionals
|general practitioner (GP)
||assists with treatment decisions and works with your specialist to provide ongoing care
||specialises in diseases of the lungs; may investigate symptoms of pleural mesothelioma and suggest initial treatments
||specialises in diseases of the digestive system; may investigate symptoms of peritoneal mesothelioma and suggest initial treatments
||specialises in reading chest x-rays, CT scans and other scans
||may drain fluid and remove tissue for diagnosis using CT scans as a guide
||yexamines cells and tissue under the microscope to determine the type and extent of mesothelioma
||conducts some biopsy procedures and performs surgery to prevent and treat symptoms of pleural mesothelioma, including radical surgery
|surgical oncologist/general surgeon*
||performs surgery to prevent and treat symptoms of peritoneal mesothelioma
||prescribes and coordinates drug therapies such as chemotherapy, immunotherapy and targeted therapy
||prescribes and coordinates the course of radiotherapy
|palliative or supportive medical specialist*
||manages pain and other symptoms to improve quality of life and wellbeing; usually works as part of a palliative care team
|palliative care team (doctors, nurses and other health professionals)
||assist with control of symptoms such as pain, breathlessness, nausea and anxiety, as well as offering emotional and spiritual support
|nurses and nurse care coordinator
||administer drugs and provide care, support and information throughout treatment
||visit you at home to supervise treatment, assess needs, and liaise with your GP or MDT
||recommends an eating plan to follow during and after treatment
|physiotherapist, occupational therapist
||help with maintaining and restoring strength and mobility during and after your treatment and may recommend equipment
||provides counselling and support, links to services and helps with practical issues
||provides emotional support and strategies to help deal with the impact of the disease
Expert content reviewers:
Dr Steven Kao, Medical Oncologist, Chris O'Brien Lifehouse, NSW; Theodora Ahilas, Principal, Maurice Blackburn Lawyers, NSW; Prof David Ball, Director, Lung Service, Peter MacCallum Cancer Centre, VIC; Cely Benchoam, Consumer; Prof Kwun Fong, Thoracic Physician, University of Queensland Thoracic Research Centre, The Prince Charles Hospital, QLD; Victoria Keena, Executive Officer, Asbestos Diseases Research Institute, NSW; Angela Kyttaridis, Social Worker, Concord Repatriation General Hospital, NSW; Dr Judith Lacey, Head of Supportive Care and Integrative Medicine, Chris O'Brien Lifehouse, NSW; Amanda Maple, 13 11 20 Consultant, Cancer Council SA; A/Prof Brian McCaughan, Thoracic Surgeon, Sydney Cardiothoracic Surgeons, Strathfield Private Hospital and University of Sydney, NSW; Jocelyn McLean, Mesothelioma Support Coordinator, Asbestos Diseases Research Institute, NSW; Kirsten Mooney, Thoracic Cancer Nurse Coordinator, WA Cancer and Palliative Care Network, Department of Health, WA; Prof David Morris, University of New South Wales, Department of Surgery, St George Public Hospital, NSW; Rod Smith, Awareness and Support Co-ordinator, Bernie Banton Foundation. We also thank the health professionals, consumers and editorial teams who have worked on previous Cancer Council resources.
2. Australian Mesothelioma Registry, Mesothelioma in Australia 2015: 5th annual report, Cancer Institute NSW, Sydney, 2016.