What is Mesothelioma?
Mesothelioma is a cancer affecting the mesothelial cells which cover most internal organs. There are two main types of mesothelioma; pleural and peritoneal.
In 2016, 774 people were diagnosed with mesothelioma in Australia.
In 2018, there were 726 deaths caused by mesothelioma in Australia.
The five year survival rate for mesothelioma is approximately 6%.
This is a type of cancer that starts in the membrane that covers the lungs. Although it develops in the chest and involves the lining of the lungs, it is not a lung cancer and it is treated differently to lung cancer.
Pleural mesothelioma is the most common type of mesothelioma, and accounts for about 90% of all mesotheliomas.
The other main type is peritoneal mesothelioma, accounting for about 10% of cases. It develops in the lining of the abdomen.
Symptoms of Mesothelioma
The main symptoms of pleural mesothelioma include:
- shortness of breath
- chest pain
- pain in the shoulder and upper arm
- sensitive skin
- loss of appetite and/or weight loss
- loss of energy
- persistent cough or a change in a person’s usual cough
- excessive sweating, especially at night.
Early signs of pleural mesothelioma are similar to other conditions and diseases, however, if you think you have been exposed to asbestos, talk to your doctor.
Symptoms of Mesothelioma
The main symptoms of peritoneal mesothelioma include:
- swollen or painful abdomen
- loss of appetite
- nausea and/or vomiting
- fever or night sweats
- bowel or urinary problems.
Less commonly, mesothelioma begins in the membrane around the heart or the reproductive organs. Growths form which gradually grow and spread to surrounding areas. Rarely, a person may develop mesothelioma in more than one place.
Causes of Mesothelioma
The only known risk factor for mesothelioma is exposure to asbestos. It can take many years after being exposed to asbestos (between 20 and 60) for mesothelioma to develop.
People who may have been exposed to asbestos at work include builders, plumbers, electricians, welders, asbestos miners, automotive industry workers and textile workers.
Sometimes mesothelioma is linked to previous radiotherapy to the chest.
Diagnosis of Mesothelioma
Tests to diagnose mesothelioma may include:
Blood tests can check your overall health and how your blood cells, liver and kidneys are working.
X-rays can help identify any abnormalities in the lungs, thickening of the pleura or fluid in the space between the lungs and the chest wall. X-rays will also help identify fluid in the abdomen.
CT (computerised tomography) scans produce three-dimensional pictures of several organs at the same time and can also scan chest lymph nodes. CT scans may also be used to see if the mesothelioma has spread to other locations.
A biopsy is when a sample of pleural or abdominal tissue is removed for examination under a microscope. It is the main procedure used to diagnose pleural mesothelioma, and can be taken in two ways: via VATS (Video-assisted thoracoscopic surgery), a type of keyhole surgery; or via CT-guided core biopsy, which is done under a local anaesthetic using a needle guided by a CT scan.
Draining Fluid from the Pleura
This can be done to relieve symptoms of breathlessness caused by pleura leaking into the pleural cavity (called pleural effusion), and in some instances, to diagnose pleural mesothelioma. People with peritoneal mesothelioma may have fluid in the abdomen (called peritoneal effusion), causing swelling and pain.
Using an ultrasound scan to guide the doctor, the fluid is drained via a needle inserted through the chest wall into the pleural cavity or into the abdomen. A sample of the fluid is then sent to a pathologist for testing.
Mesothelioma can be difficult to diagnose as the cells can look similar to other types of cancer cells. Combining results from fluid samples with information from an x-ray and CT scan can provide an acceptable level of certainty of a diagnosis.
If mesothelioma is diagnosed, further tests are usually done to find out if the disease has spread to other parts of the body, such as CT scans; FDG-positron emission tomography (FDG-PET); mediastinoscopy (used to examine and sample lymph nodes at the centre of the chest); or endobronchial ultrasound (EBUS).
Treatment for Mesothelioma
Although there is currently no cure for mesothelioma, active treatment is recommended for some people. This can include chemotherapy, radiation therapy, surgery, or a combination of these treatments. It can help some people to achieve a longer period of control over the disease.
The two types of mesothelioma are treated differently.
Chemotherapy drugs aim to destroy cancer cells while causing the least possible damage to healthy cells. The most commonly used chemotherapy drugs for treating pleural mesothelioma include pemetrexed with cisplatin or carboplatin. Chemotherapy for pleural mesothelioma aims to prolong life and shrink the cancer as well as improving quality of life.
Chemotherapy is sometimes used for peritoneal mesothelioma either on its own or before or after surgery. Chemotherapy is given directly into the abdomen for people with peritoneal mesothelioma.
Radiation Therapy (radiotherapy)
Radiation therapy (also known as radiotherapy), the use of x-rays to kill or damage cancer cells, can be used at different stages of pleural mesothelioma and in different ways. For example, it can relieve symptoms such as pain caused by tumours, and it can be given after chemotherapy or surgery, to help kill remaining cancer cells.
Radiation therapy is rarely used to treat peritoneal mesothelioma but may be used to relieve pain or kill any cancer cells that remain after surgery or chemotherapy.
There are two main types of operations considered for actively treating pleural mesothelioma: extrapleural pneumonectomy (EPP), which removes the tumour and the pleura, the affectedlung, the diaphragm and a portion of the lining of the heart; or a pleurectomy with pulmonary decortication (PD), which removes the pleura and as much disease as possible.
Surgery for peritoneal mesothelioma may be possible if the cancer has not spread. In this operation, called a peritonectomy, the surgeon removes parts of the peritoneum where the mesothelioma is growing.
Trimodality therapy uses a combination of chemotherapy, radiotherapy and major surgery. It is used to treat some people with mesothelioma.
When mesothelioma is diagnosed at an advanced stage, the main goal of treatment is to manage the symptoms and keep them under control as long as possible.
Treatments can include surgery to improve breathlessness caused by fluid build-up. VATS (video-assisted thoracoscopic surgery) involves removing some of the lining of the chest wall and lung. During the procedure, sterile talcum powder is injected into the pleural cavity, causing inflammation that closes the pleural cavity and helps prevent fluid from building up again.
More extensive open surgery can also be undertaken to drain fluid build-up in the lungs, or to relieve pain in the chest. For people not suitable for VATS or open surgery, an indwelling pleural drain may be used, which allows fluid to be drained 1-2 times a week, depending on how quickly the fluid builds up again.
The treatment team will discuss with the person, suitable treatment options to assist with other symptoms such as sleeplessness, pain, fatigue, loss of appetite and weight loss.
In some cases of mesothelioma, your medical team may talk to you about palliative care. Palliative care aims to improve your quality of life by alleviating symptoms of cancer.
As well as slowing the spread of mesothelioma, palliative treatment can relieve pain and help manage other symptoms. Treatment may include radiotherapy, chemotherapy or other drug therapies.
Depending on your treatment, your treatment team may consist of a number of different health professionals, such as:
- GP (General Practitioner)- looks after your general health and works with your specialiststo coordinate treatment.
- Radiologist- interprets diagnostic scans (including CT, MRI and PET scans).
- Respiratory physician- investigates symptoms, is involved in diagnosis and determines initial treatment options.
- Interventional radiologist- uses imaging scans (CT, MRI, ultrasound) to guide needles and other instruments for draining fluid and removing tissue for diagnosis.
- Pathologist- examines cells and tissues under a microscope.
- Thoracic (chest) surgeon- diagnoses and performs surgery for cancer and other diseases of the lungs and chest.
- Medical oncologist- prescribes and coordinates the course of chemotherapy.
- Radiation oncologist- prescribes and coordinates radiation therapy treatment.
- Palliative care team- assist with control of symptoms and help maintain quality of life as well as offering a range of support services.
- Cancer nurses- assist with treatment and provide information and support throughout your treatment.
- Other allied health professionals- such as social workers, pharmacists and counsellors.
Screening for Mesothelioma
There is currently no screening for mesothelioma available in Australia.
Reducing your exposure to asbestos is the most likely way to lower your risk of mesothelioma, whether at work or in the home. Australia has a code of practice on managing and controlling asbestos: www.safeworkaustralia.gov.au.
Prognosis for Mesothelioma
It is not possible for a doctor to predict the exact course of a disease, as it will depend on each person’s individual circumstances. However, your doctor may give you a prognosis, the likely outcome of the disease, based on the type of mesothelioma you have, the test results, the rate of tumour growth, as well as your age, fitness and medical history.
In general, the earlier cancer is diagnosed, the better the outcome. However, mesothelioma is often diagnosed once it has advanced, as often the early symptoms can go unnoticed. Although it is more difficult to treat advanced cancer successfully, it may be possible to keep the disease under control for months or years, and quality of life can be improved by relieving the symptoms.
Copy edited from Understanding Pleural Mesothelioma, Cancer Council Australia © 2019. Last medical review of source booklet: August 2019.
Australian Institute of Health and Welfare. ACIM (Australian Cancer Incidence and Mortality) Books. Canberra: AIHW.