Epidemiology and Clinical Aspects of Malignant Pleural Mesothelioma.

Fraser Brims

doi:10.3390/cancers13164194

Abstract

Simple SummaryMesothelioma is a cancer of the lining of the lungs caused by breathing in asbestos fibres. Asbestos was widely used in industry in the last century in most developed countries and is still present in many older buildings to this day. There is no known safe level of asbestos exposure. Symptoms of mesothelioma can include worsening breathlessness, chest pain and loss of weight. There is no cure, and the treatment of mesothelioma is limited, although there have been some recent improvements in therapy. Survival is very variable although most people live for around one year after diagnosis. Efforts to improve and maintain the quality of life for patients with mesothelioma remain a priority.Mesothelioma is a cancer predominantly of the pleural cavity. There is a clear association of exposure to asbestos with a dose dependent risk of mesothelioma. The incidence of mesothelioma in different countries reflect the historical patterns of commercial asbestos utilisation in the last century and predominant occupational exposures mean that mesothelioma is mostly seen in males. Modern imaging techniques and advances in immunohistochemical staining have contributed to an improved diagnosis of mesothelioma. There have also been recent advances in immune checkpoint inhibition, however, mesothelioma remains very challenging to manage, especially considering its limited response to conventional systemic anticancer therapy and that no cure exists. Palliative interventions and support remain paramount with a median survival of 9–12 months after diagnosis. The epidemiology and diagnosis of mesothelioma has been debated over previous decades, due to a number of factors, such as the long latent period following asbestos exposure and disease occurrence, the different potencies of the various forms of asbestos used commercially, the occurrence of mesothelioma in the peritoneal cavity and its heterogeneous pathological and cytological appearances. This review will describe the contemporary knowledge on the epidemiology of mesothelioma and provide an overview of the best clinical practice including diagnostic approaches and management.

Highlights

Malignant pleural mesothelioma (MPM) is a cancer caused by exposure to asbestos that only became widely recognised in the second half of the last century
The AMPLE study was a multicentre randomised controlled trial that demonstrated that patients with malignant pleural effusion spend less time in hospital after indwelling pleural drainage catheter (IPC) placement than those with a chest drain and attempt at pleurodesis, but there was no difference in objective dyspnoea scores, quality of life or survival [81]
Historical trends in asbestos utilisation in the last century continue to drive the incidence of mesothelioma, asbestos mining and manufacture continues in many countries today

Summary

Introduction

Malignant pleural mesothelioma (MPM) is a cancer caused by exposure to asbestos that only became widely recognised in the second half of the last century. Estimates of latency continue to be revised as exposed populations age; the Western Australia Mesothelioma Registry initially reported a time since first exposure to diagnosis of those diagnosed between 1960–1979 of 26 years [8], with the most recent estimate of latency in those diagnosed between 2010–2019 being 52 years [30] This observation is, in part, not surprising as the period of highest asbestos use, and exposure of the population in most developed countries, is fixed in the 1960–1970 s, and as the population at risk grows older, the latency will be prolonged. While pleural fluid aspiration alone is highly desirable and convenient alone for some patients, it should be noted that with advances in immunotherapy there is an increasing requirement for histological samples to establish which therapeutic approaches may be appropriate and, in addition, entry into many clinical trials may require a histological confirmation of mesothelioma

Clinical Presentation and Investigations

Treatment of Mesothelioma

Prognosis

Findings

Conclusions