Clinical features and epidemiology of malignant pleural mesothelioma in west Glasgow 1987-1992

Our plain-English summary of Clinical features and epidemiology of malignant pleural mesothelioma in west Glasgow 1987-1992, by A.N. McLean, K.R. Patel (Scottish Medical Journal, 1997).

The study

• Authors: A.N. McLean, K.R. Patel
• Journal: Scottish Medical Journal
• Published: 1997;42(2):37-9
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Malignant pleural mesothelioma is almost exclusively caused by exposure to asbestos dust. Recent epidemiological studies have suggested that the national incidence of disease may continue to rise until 2020 and that asbestos exposure in the building trade may be replacing shipyard related exposure as the main source of disease. The objective of the study was to determine if the incidence of malignant pleural mesothelioma was rising in the west of Glasgow from 1987-1992 and whether there had been a change in clinical features compared to previous studies from the same population. Case notes identified from coded returns and the local cancer registry were retrospectively examined: 144 cases were identified. This is an increase in incidence of over 50% compared to the previous study but the yearly incidence did not rise over the period studied. The clinical features and survival times have not changed since previous studies: median survival remains 30 weeks. Only three patients were given definitive treatment reflecting the lack of effective therapy. We suggest that the incidence of mesothelioma in the population studied may already have peaked resulting from the decline in the local shipyard industry over 20 years ago. Non-shipyard sources of asbestos exposure may be less important in this area.

In plain English

The authors reviewed the hospital case notes of everyone diagnosed with malignant pleural mesothelioma in their hospital's catchment area in west Glasgow from 1987 to 1992. They found 144 cases. Of these, 132 (92%) were men, and the mean age at diagnosis was 67. Seventy-four were recorded as shipyard workers, and 92 (64%) had definite asbestos exposure recorded. Six women had been exposed to asbestos on their husbands' clothes. Yearly cases ranged from 21 to 27, with no significant difference in the annual rate across the six years. The mean of 24 cases a year compared with the authors' estimate of 12 a year for 1980-86 in the same population. Median survival was 30 weeks from diagnosis, and only three patients had definitive surgery. The authors concluded that they may be seeing the peak of shipyard-related mesothelioma locally, and said more years of data would be needed to confirm this. They noted that the population may be too small to show yearly changes. They also noted that some of the 24 cases diagnosed without tissue confirmation may have been misdiagnoses.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective review of hospital case notes for all patients diagnosed with malignant pleural mesothelioma in one hospital catchment area (case series)
• Who was studied: 144 patients with malignant pleural mesothelioma from the hospital catchment area in the west of Glasgow, Scotland, diagnosed 1987-1992, identified from the West of Scotland Cancer Surveillance Unit registry and hospital admission returns
• Exposure: Occupational asbestos exposure, mainly in the Clyde shipyards. 74 patients were directly recorded as shipyard workers, and 92 (64%) had definite asbestos exposure recorded. Of the remaining 52, only nine had not worked in shipyards or engineering factories. Six women had been exposed via dust on their husbands' clothes, and three women had worked with asbestos. Fiber types and doses were not reported.
• Main results:
  • Of the 144 patients, 132 (92%) were male. The mean age at diagnosis was 67 (range 38-92) years.
  • 74 patients were directly recorded as working in the shipyards.
  • Among the women, six had been exposed to asbestos on their husbands' clothes.
  • Yearly cases were 22 (1987), 26 (1988), 21 (1989), 27 (1990), 23 (1991) and 25 (1992). There was no significant difference in the annual rate over the six years.
  • The mean was 24 cases per year in this series. The authors estimated a mean of 12 per year for 1980-86 in the same population, adjusting an earlier study that counted only histologically proven cases.
  • In a 1990 west Glasgow population of 221,120, the annual crude rate was approximately 108 per million. The authors compared this with an estimated spontaneous rate of around 1 per million in non-asbestos-exposed populations.
  • A further 23 cases reported to the Cancer Surveillance Unit as pleural mesothelioma were incorrectly coded, which the authors described as 16% over-reporting. Most were adenocarcinoma of pleura or malignant peritoneal mesothelioma.
  • The most common symptoms were dyspnoea (66%), pain (51%) and weight loss (33%).
  • Of 138 available chest radiograph reports, 132 (96%) showed pleural effusion and 116 (84%) showed pleural thickening. Pleural plaques were recorded on 12 (9%), and two showed shadowing in keeping with pulmonary asbestosis.
  • 24 patients were diagnosed without histological confirmation. Of the 120 initial blind biopsies, 65 (54%) were positive.
  • Median survival was 30 (range 0-172) weeks from diagnosis and 45 weeks from symptom onset. Age and mode of presentation did not predict prognosis.
  • 38 patients (26%) survived more than one year and 11 (8%) more than two years. 35 (24%) survived under three months.
  • Three patients had definitive surgery and one received chemotherapy.
  • 28 patients (23%, as printed) developed tumour tracking through the biopsy site.
• The authors' conclusion: The authors concluded that they may be seeing the peak of shipyard-related mesothelioma in west Glasgow, two to three decades after the local shipbuilding decline. They suggested non-shipyard sources may be less important in this area, and said further analysis over the next few years would be needed to confirm this.
• Limitations the authors state:
  • The population may be too small to detect a yearly difference of the size reported nationally.
  • Cases diagnosed without definitive histology (17%) may have included some misdiagnoses.
  • Some of the rise compared with earlier years may reflect clinicians' and pathologists' growing experience in diagnosing mesothelioma.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Epidemiology, Pleural Mesothelioma, Asbestos Exposure, Cancer Registry, Median Survival, Mesothelioma.

Related studies

• Asbestos and lung cancer in Glasgow and the west of Scotland — H. De Vos Irvine, D.W. Lamont, et al. (1993)
• The epidemiology and clinical features of asbestosis and related diseases — P.C. Elmes (1966)
• Malignant pleural mesothelioma in western Glasgow 1980-6 — G. Hulks, J.S. Thomas, et al. (1989)
• Clinical features of adenosquamous lung carcinoma in 127 patients — K.S. Sridhar, M.J. Bounassi, et al. (1990)
• Clinical Features and Treatment Outcome of Malignant Pleural Mesothelioma — M. Mencoboni, R.A. Filiberti, et al. (2017)
• Clinical Features in Patients With Malignant Pleural Mesothelioma With 5-Year Survival and Evaluation of Original Diagnoses — J. Paajanen, S. Laaksonen, et al. (2020)

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