What is Mesothelioma?
Mesothelioma is a very aggressive, treatment resistant cancerous tumour that affects the lining that covers the outer surface of most of the body’s organs. The most common form is pleural mesothelioma, this affects the pleura of the lung (the thin membrane surrounding the lungs). The second most common form is peritoneal mesothelioma, this affects the lining of the abdominal cavity. Mesothelioma can also affect the lining of the heart (pericardial mesothelioma) and the testes (testicular mesothelioma).
It is caused by high levels of exposure to asbestos, and inhalation of the fibres during an individuals working or domestic life. Many will be surprised to know that there is a stronger link between asbestos exposure and mesothelioma than smoking and lung cancer.
One of the defining features about this cancer is that there is a very long latency period between exposure to asbestos and experiencing symptoms of the disease. Commonly the delay can be between 10 and 50 years.
Unfortunately due to how long the illness is dormant for, by the time mesothelioma is diagnosed it may have progressed to a severe level and therefore the prognosis is often negative.
How mesothelioma is diagnosed
Like other asbestos related diseases, mesothelioma can often only be diagnosed through a chest X-ray or CT scan. Mesothelioma is made even harder to diagnose because the disease often starts as tiny lumps or nodules in the pleura that won’t initially be picked up by X-ray or scan until they grow in size. Often a number of tests are required to diagnose the cancer, and by this time a misdiagnosis may result in being identified as another illness.
Because the cancerous mesothelioma cells can irritate the pleura, sometimes a pocket of fluid will develop. This is known as pleural effusion and because mesothelioma is sometimes present in this fluid, a sample can be taken to help diagnose mesothelioma.
Biopsies are almost always used to confirm the presence of pleural mesothelioma. This requires a sample to be taken from the pleura or the lymph nodes. The biopsy may be conducted in a variety of ways, including:
A thoracoscopy is a form of biopsy that will allow a medical professional to look directly at the pleura and other structures of the lungs. The thoracoscopy will be guided to the thicker areas of the pleura, allowing the doctor to take a biopsy of that at risk area.
CT or ultrasound guided biopsy
Following a local anaesthetic, a medical professional can pass a special needle through the skin which is then guided using ultrasound or a CT scanner to the area of the lungs where mesothelioma may have developed. Once the needle has reached the area it can dissect a sample of the tissue for biopsy.
If a doctor thinks that the mesothelioma may have spread to the lymph nodes then a mediastinoscopy may be required. Often conducted under general anaesthetic, this procedure will allow doctors to look at the lymph nodes which are located in the space in between the lungs. This will allow biopsies to be taken if they are required.
Sadly mesothelioma is not curable and the outlook for patients is often grim. However, there are a number of treatments available that can allow the sufferer to live a better quality of life. The forms of treatment available also depend on factors such as the stage of the cancer, whether it has metastasised and the general health of the patient.
If the mesothelioma is at stage 2, 3 or 4, then radiotherapy can be administered. It is a treatment that will reduce the impact of the symptoms and potentially slow down the growth of the tumour. Sometimes radiotherapy will be given after a separate procedure to remove fluid from the lungs. This will potentially prevent mesothelioma spreading further.
Anticancer drugs are often injected into a vein and the regularity of this treatment is determined by the severity of the cancer. Sometimes chemotherapy can be used as more of a controlling measure, as it can help prevent a tumour from growing if it has reached a stage where it is inoperable.
Surgery is often used as a palliative measure, designed to remove as much of the tumour as possible. This approach will relieve the impact of the symptoms.
Removing the pleura and lung
Sometimes these treatments are only available for people where mesothelioma has been diagnosed at an early stage. It requires the patient to have strong heart and lung function, but in some cases may allow a person to live longer when it is used alongside radiotherapy and chemotherapy.
Immunotherapy is currently an emerging treatment for mesothelioma. Immunotherapy uses drugs to stimulate a person’s own immune system to target and kill cancer cells. It has been successful in its use for other cancers, and clinical trials have shown that it can be successful in treating mesothelioma. The treatment is beneficial because it usually results in relatively few side effects in comparison to other treatments, such as chemotherapy and radical surgery, and does not damage healthy cells.