21st February 2025

Asbestos-related lung conditions

Asbestos is a naturally occurring fibrous material previously used widely in construction and manufacturing. Exposure has now been linked to a range of medical conditions, including asbestosis, pleural disease and malignancy.

Deaths related to occupational asbestos exposure should be referred to the coroner and sufferers of asbestos-related disease may be entitled to compensation.

Asbestosis

Asbestosis is an interstitial lung disease caused by progressive pulmonary fibrosis in response to inhaled asbestos fibres. 

Presentation of asbestosis

The initial symptoms of asbestosis are usually progressive dyspnoea and a dry cough. These usually develop decades after asbestos exposure. 

Signs may include bilateral fine crackles on auscultation (usually starting at the bases), reduced chest expansion and finger clubbing.

Investigation of asbestosis

Initial screening is with a chest X-ray, which may show bilateral interstitial changes. The presence of asbestos-related pleural changes may support a diagnosis of asbestosis as the cause of interstitial changes. Chest X-ray changes can be subtle in early disease so more sensitive HRCT may be considered.

Pulmonary function testing will usually demonstrate a restrictive pattern with reduced TLCO but also reduced KCO as lung parenchyma is affected. If there has been a significant smoking history, there may also be an obstructive element to the results.

Lung biopsy is not normally required. 

Management of asbestosis

There is currently no disease-modifying treatment for asbestosis so focus should be on supportive treatment, including avoiding further asbestos exposure, smoking cessation, pulmonary rehabilitation, long-term oxygen therapy and pneumococcal and influenza vaccines.

Asbestos-associated pleural disease

Asbestos exposure can lead to a range of benign pleural disease.

Pleural plaques

Pleural plaques are focal areas of benign pleural thickening which develop as a result of asbestos exposure. They are normally bilateral, may be calcified, and typically overlie the 6th to 9th ribs. The apices and costophrenic recesses are usually spared.

Pleural plaques are usually asymptomatic and do not require any intervention or follow-up.

Diffuse pleural thickening

More extensive pleural thickening can also occur following exposure to asbestos (although diffuse pleural thickening can also develop in response to other processes such as infection, inflammation or pleural effusions).

Diffuse pleural thickening is differentiated from pleural plaques by dimensions on CT imaging. In addition, it is often present in the costophrenic recesses (unlike pleural plaques).

Diffuse pleural thickening may restrict lung expansion and lead to breathlessness. Pulmonary function testing will usually demonstrate a restrictive pattern with reduced TLCO but normal KCO.

Benign asbestos pleural effusion (BAPE)

Small unilateral benign pleural effusions can occur in patients who have been exposed to asbestos. The effusions are exudative.

BAPE is usually asymptomatic and may resolve spontaneously but should be investigated if identified given the increased risk of lung malignancy in this patient group. 

Mesothelioma

The malignancy most strongly associated with asbestos exposure is malignant mesothelioma. 

Asbestos exposure also increases the risk of developing other types of lung cancer. The investigation and management of these should be the same as for lung cancer of any other cause (see Lung cancer).

Pathology and risk factors in mesothelioma

Exposure to asbestos is the main risk factor for mesothelioma, and around 80% of patients with mesothelioma have a history of this. The average latency between exposure and development of mesothelioma is 20 to 40 years. 

Around 90% of mesothelioma cases are pleural, though mesothelioma can also develop in the peritoneum (5-10%), pericardium and testes (<1% each).

Presentation and investigation of mesothelioma

The most common symptoms of pleural mesothelioma include chest pain and dyspnoea, as well as constitutional symptoms such as fever and weight loss. Pleural effusions are often present at diagnosis. 

NICE suspected cancer guidelines for mesothelioma are summarised below:

Table 7 NICE guidelines for suspected mesothelioma

Chest X-ray is recommended as the initial screening investigation. Following an X-ray, A CT of the chest and upper abdomen should be offered if there is high clinical suspicion of malignancy. CT signs suggestive of mesothelioma include nodular pleural thickening, hilar or mediastinal lymphadenopathy and invasion into surrounding structures such as the chest wall.

Even following CT, it can be difficult to differentiate benign from malignant pleural disease on imaging alone. If present, pleural effusions should be tapped for cytology. Yield can be low, so tissue biopsy is often required in addition, either by VATS (video-assisted thoracoscopic surgery) or transcutaneous CT-guided biopsy.

A PET scan should be considered to assess for regional or distant spread of disease.

Management of mesothelioma

Mesothelioma has a poor prognosis, with a median survival of 10 to 15 months.

In some cases, surgery with curative intent can be considered, usually combined with chemotherapy or radiotherapy.

In most cases, treatment will be palliative. Surgery, radiotherapy and systemic therapies (including chemotherapy, angiogenesis inhibitors and immunotherapy) can all play a role in palliative management. Platinum chemotherapy (usually cisplatin/carboplatin + pemetrexed) has been the mainstay of systemic treatments.

Pleurodesis and indwelling pleural catheters are useful in managing recurrent effusions.

References

• Rosenman K. Asbestosis [Internet]. BMJ Best Practice. 2020 [cited 2022 Jan 31]. Available from: https://bestpractice.bmj.com/topics/en-gb/650
• Thomas A, del Rivero J, Hesdorffer M. Mesothelioma [Internet]. BMJ Best Practice. 2021 [cited 2022 Jan 31]. Available from: https://bestpractice.bmj.com/topics/en-gb/1184
• Woolhouse I, Bishop L, Darlison L, De Fonseka D, Edey A, Edwards J, et al. British Thoracic Society Guideline for the investigation and management of malignant pleural mesothelioma. Thorax [Internet]. 2018 Feb 14 [cited 2019 Dec 18];73(Suppl 1):i1–30. Available from: https://thorax.bmj.com/content/73/Suppl_1/i1
• Popat S, Baas P, Faivre-Finn C, Girard N, Nicholson AG, Nowak AK, et al. Malignant pleural mesothelioma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Annals of Oncology [Internet]. 2022 Feb [cited 2022 Jan 31];33(2):129–42. Available from: https://www.annalsofoncology.org/article/S0923-7534(21)04820-1/fulltext
• King T. Asbestos-related pleuropulmonary disease [Internet]. Flaherty K, Hollingsworth H, editors. www.uptodate.com. 2021 [cited 2022 Jan 31]. Available from: https://www.uptodate.com/contents/asbestos-related-pleuropulmonary-disease 
• Asbestos-related conditions [Internet]. British Lung Foundation. 2021 Jan [cited 2022 Jan 31]. Available from: https://www.blf.org.uk/sites/default/files/Abestos_and_your_lungs_V4_downloadable_PDF.pdf
• British Thoracic Society. Pleural Plaques Information for Health Care Professionals [Internet]. NHS Greater Glasgow and Clyde. Department of Health; 2011 [cited 2022 Mar 14]. Available from: http://library.nhsggc.org.uk/mediaAssets/Respiratory%20Medicine/BTS%20Plueral_Plaques299912_acc.pdf