9th January 2024

Asbestos-related lung disease

The mesothelium is a protective lining of various organs, and depending on the organ, it can be called the pleura, peritoneum, pericardium or tunica vaginalis. It can, therefore, lead to symptoms related to these different organ systems. Asbestos exposure can cause benign or malignant disease within the mesothelium – benign changes are often inconsequential, but mesothelioma is an incurable cancer.

Asbestosis is a form of basal lung fibrosis. It is caused by inhalation of asbestos fibres, and disease occurs many years after exposure. A chest X-ray may be entirely normal, so a high-resolution CT chest is necessary to visualise the lung parenchyma. Pulmonary function tests show a restrictive deficit, and these investigations, alongside a strong exposure history is usually enough to make a diagnosis. A lung or pleural biopsy is rarely needed.

Pleural effusions, plaques and thickening can occur as asbestos-related lung disease. The pleural effusions can resolve spontaneously, and plaques/thickening may be found with a chest X-ray. Pleural plaques are not known to cause any symptoms and do not lead to mesothelioma, so patients with these X-ray or CT findings can be reassured and discharged. Pleural thickening can lead to respiratory symptoms.

Mesothelioma is malignant change of the mesothelium (in this case, we are limiting the topic to the pleura). The exact mechanism is unknown but is suspected to be due to lymphatic spread of asbestos fibres to the pleura. The diagnosis of mesothelioma is made with a biopsy, often as a VATS procedure. If a pleural effusion is present, then this can also be drained.

Treatment of asbestos-related lung disease is largely based around symptomatic relief. For example, treatment of a pleural effusion would involve insertion of a chest drain until dry, and then using talc pleurodesis. Conservative measures such as smoking cessation services, vaccinations and supplemental oxygen can be offered.

Patients with mesothelioma are offered palliative chemo- and radiotherapy, as well as palliative surgical therapy. Only around 45% of patients survive mesothelioma 1 year after the diagnosis is made.

Since asbestos-related lung disease is related to occupational exposure, patients have a legal claim to compensation. Pleural plaques are an exception because they are not known to cause any symptoms.