Key learning points

  • Mesothelioma is an aggressive cancer usually caused by exposure to asbestos several decades before symptoms arise 
  • Presenting symptoms are often dyspnoea and/or chest pain but patients may have fatigue, anorexia, weight loss and/or sweats
  • A thorough history of a patient’s previous occupations may uncover asbestos exposure, which should prompt urgent referral for diagnosis and treatment
  • Drainage of pleural effusions should improve symptoms of dyspnoea, and preventing fluid re-accumulation can improve the patient’s quality of life
  • There is no cure but early diagnosis and multidisciplinary team care is essential for limiting morbidity and prolonging survival

Introduction

Malignant pleural mesothelioma is an aggressive cancer with a poor prognosis that is most often caused by having previous exposure to asbestos. Although asbestos production and supply was prohibited in the UK in 1999, deaths from mesothelioma continue to increase and the UK has some of the highest rates of mesothelioma in the world. This is predominantly due to the 40-year latency from first exposure, and improved case identification.1,2 Individuals who worked in the construction and shipbuilding industries where contact with asbestos was common are at particular risk of mesothelioma, but exposures are not always readily identifiable.3 

Case study

Mr Daniels, aged 72, presented to his GP with progressive exertional dyspnoea. He was generally well and had never smoked. There was no recent history of cough, chest pain or fever. He was a retired builder and recalled removing asbestos from industrial ovens as an apprentice. 

On examination, he appeared well but there was dullness to percussion and reduced breath sounds at the left base. Chest radiography confirmed a moderate left-sided pleural effusion. He was urgently referred to the local pleural service. Thoracocentesis, where a needle is inserted into the pleural space between the lungs and the chest wall, was arranged with 1.2L fluid drained, and his dyspnoea improved. The pleural sample was exudative with no malignant cells seen. 

Mr Daniels proceeded to local anaesthetic thoracoscopy to examine the pleural lining and surface of the lungs. Biopsies were taken and, given the macroscopically abnormal pleura, talc pleurodesis was performed. The biopsies were diagnostic for malignant pleural mesothelioma. He currently awaits staging and discussion with the mesothelioma multidisciplinary team (MDT).  

Discussion

Patients predominantly present with dyspnoea, chest pain, or both. Chest pain can worsen if there is invasion of ribs or intercostal nerves. Other symptoms include fatigue, anorexia, weight loss and sweats.1,4,5 Patients with symptoms suggestive of mesothelioma, particularly if they have a history of asbestos exposure, should undergo an urgent chest X-ray.2

Findings associated with mesothelioma on chest radiography include pleural effusion, nodular pleural thickening, fissural thickening or a localised mass lesion. CT allows more precise evaluation and staging, while ultrasound allows identification of pleural fluid, pleural thickening and nodularity.1,4 

Further investigation often requires thoracentesis, however, cytological yield is low and biopsies are often needed. This can be done percutaneously with image guidance or under direct vision at thoracoscopy using local or general anaesthesia. Thoracoscopy offers simultaneous therapy and diagnosis, larger biopsies and an overall diagnostic sensitivity of approximately 93%.1,6,7 

There is no cure for mesothelioma and median survival is 10–12 months.8 Surgery is controversial and limited to select patients, and radiotherapy is typically only used palliatively. Chemotherapy has the best evidence base and has been shown to improve survival for some patients. Immunotherapy has shown promise in recent studies but is not yet available in the UK outside of clinical trials.1,2 

Drainage of pleural effusions improves dyspnoea, and prevention of fluid re-accumulation can improve quality of life. Patients now have a choice of options including therapeutic aspiration, pleurodesis, or indwelling pleural catheter insertion.1 

Referral to specialist palliative care is appropriate for a range of issues including unresolved physical symptoms and complex psychosocial or spiritual needs.1,4 However, routine early referral does not appear to confer any benefit in health related quality of life or mood.9

MDT discussion and mesothelioma specialist nurses also have an integral role in providing and coordinating the specialist care needs of patients and their carers.

In England and Wales all deaths from mesothelioma should be referred to the coroner, who will decide if a post mortem is required.10 Patients and their families may be able to claim for compensation in the civil courts. In general, there must be evidence of the employer’s negligence or breach of statutory duty, however, each case is decided on its own merits and specific legal advice should be sought.11 The mesothelioma team will be able to provide patients with details of available legal assistance.

Summary

It is important to identify mesothelioma at an early stage, and symptoms of dyspnoea and chest pain, particularly in people with an occupational background suggestive of asbestos exposure, should merit urgent referral for further investigation and treatment. GPs have an integral role in the diagnosis and management of the condition.5

Dr Vineeth George, clinical fellow in pleural disease, Oxford Centre for Respiratory Medicine and Professor Najib Rahman, professor of respiratory medicine, University of Oxford and consultant respiratory physician, Oxford Centre for Respiratory Medicine

This project was initiated and funded by Teva Respiratory. Teva have had no influence over content. Topics and content have been selected and written by independent experts.

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