Malignant mesothelioma in south east England: clinicopathological experience of 272 cases

Our plain-English summary of Malignant mesothelioma in south east England: clinicopathological experience of 272 cases, by D.H. Yates, B. Corrin, P.N. Stidolph, et al (Thorax, 1997).

The study

• Authors: D.H. Yates, B. Corrin, P.N. Stidolph, K. Browne
• Journal: Thorax
• Published: 1997;52(6):507-12
• Cited by: 161 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Malignant mesothelioma is a rare pleural tumour associated with asbestos exposure. The proportion of malignant mesothelioma unrelated to asbestos exposure, and any differentiating features between exposed and unexposed cases, are not well described. This study describes occupational, clinical, and pathological features in a large cohort of cases of malignant mesothelioma from south east England.

Methods: All 272 cases from this region were studied, either in life or after death when necropsy examination suggested malignant mesothelioma. Detailed information was gathered regarding the occupational history, clinical course, and mode of death. Necropsies were performed in 98% of cases. Lung tissue was examined histologically to confirm the diagnosis, subtype of tumour, presence or absence of asbestosis and asbestos bodies.

Results: Exposure to asbestos was documented in 87% of cases, while in the remainder, no asbestos exposure was found nor were asbestos bodies seen; 94.5% were pleural, 5.1% peritoneal, and 0.4% pericardial. Right sided tumours were more common than left sided tumours (ratio 1.6:1). Patients usually presented with breathlessness and chest pain, but 33% presented with pleural effusion in the absence of chest pain. The mean (SD) time from first exposure to asbestos to symptoms was 40 (12) years with a median (interquartile range (IQR) survival of 14 (12.5) months. The median (IQR) survival time in sarcomatous, epithelial, and mixed cell type malignant mesothelioma was 9.4 (10) months, 12.5 (18) months, and 11 (14) months, respectively, and was significantly greater in cases detected by chance. Clinical features were similar in asbestos related and non-asbestos related malignant mesothelioma.

Conclusions: In south east England most cases of malignant mesothelioma are associated with asbestos exposure. Clinical features do not differentiate between asbestos related and non-asbestos related disease.

In plain English

This study described 272 deaths from malignant mesothelioma in 1987 in the London Medical Boarding Centre area of south east England (252 men). Necropsies were performed in 267 cases (98.1%). Occupational asbestos exposure was found in 86.8% of cases (212 definite, 24 probable). In 30 cases there was no exposure history and no asbestos bodies were seen. The asbestos fiber type could not be identified. There were 257 pleural tumours, more often right sided (157) than left sided (99), plus 14 peritoneal and one pericardial. Mean age at death was 65.2 years. Median survival from symptom onset was 14 months. In the 168 cases with verified dates, mean latency from first exposure to death was 41.4 years. Sarcomatous tumours had significantly shorter survival than the other types. In the 34 cases without occupational exposure, the male to female ratio was 1.35:1, against 12.6:1 for the whole group. The authors concluded that no features separated asbestos related from non-asbestos related cases. They noted that selection bias could not be ruled out and a few cases may have gone unreported.

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: Descriptive clinicopathological case series of mesothelioma deaths referred in one region in one calendar year, using compensation-system records and necropsy
• Who was studied: 272 cases accepted as malignant mesothelioma (252 men), out of 285 referred. These were deaths in 1987 in the London Medical Boarding Centre area, which covers the industrial south east of England. Mean age at death was 65.2 (SD 9.5) years, range 39 to 92.
• Exposure: Asbestos exposure was classed from occupational histories and asbestos bodies in lung tissue as definite, probable, non-occupational or none. The asbestos fiber type could not be identified; the authors state that mixed exposure was usual in the UK. Reliable information on duration of exposure was available in 166 cases (61%), with a mean duration of 19 (SD 13) years.
• Main results:
  • Occupational exposure to asbestos was found in 86.8% of cases: 212 definite and 24 probable exposures. The remaining cases were 4 with possible non-occupational exposure, 30 with no exposure, and 2 unclassified.
  • There were 257 pleural tumours, with a right sided predominance (157 right, 99 left; ratio 1.6:1). There were also 14 peritoneal tumours (5.1%) and one pericardial mesothelioma.
  • For all cases, median survival from symptom onset was 14 (interquartile range 12.5) months, with a range of 0 to 91 months. Survival was significantly shorter in peritoneal mesotheliomas (7 (4) months).
  • In the 168 cases with verified dates of first exposure, mean latency (first exposure to death) was 41.4 (SD 11.7) years, with a range of 15 to 67 years. Latency was longer in peritoneal cases at 46.7 (11.3) years (p<0.05).
  • Of 250 cases with histological subtyping, 83 were sarcomatous, 81 epithelial and 84 mixed; 2 could not be typed. Median survival was 12.5 (18) months for epithelial, 11 (14) months for mixed and 9.4 (10) months for sarcomatous tumours. Sarcomatous survival was significantly shorter (p<0.05). Frequency of metastasis did not differ significantly between subtypes.
  • Pleural effusion with breathlessness but without chest pain was the presenting feature in 90 cases (33%).
  • In the 10 cases found by chance on a routine chest radiograph taken for another reason, median survival was significantly longer at 21 (4) months (p<0.05).
  • Asbestosis was more common in peritoneal than in pleural mesotheliomas: 5 (35.7%) versus 10 (3.9%) (p<0.01). Asbestos bodies were present in 125 cases (46%). Pleural plaques were found at necropsy or on radiographs in 78 (28.7%).
  • In the 34 cases with no occupational exposure, the male to female ratio was 1.35:1, significantly different from 12.6:1 in the whole group. These cases had a lower mean age at death (63.0 versus 65.4 years) and shorter survival, but these differences were not statistically significant.
• The authors' conclusion: The authors concluded that most cases in the region were associated with asbestos exposure. They found no features (site, side or clinical behaviour) that separated asbestos related from non-asbestos related mesothelioma.
• Limitations the authors state:
  • The referral system should have reduced occupational selection bias, but the authors state that such a bias cannot be discounted.
  • A small number of cases may have gone unreported because asbestos exposure seemed extremely improbable.
  • The 87% exposure figure is likely to reflect some selection at source. A history of asbestos exposure may make a necropsy and a pathological diagnosis of mesothelioma more likely.
  • The classification criteria made a case more likely to be classed as asbestos exposed than otherwise.
  • Exposure duration figures for peritoneal cases are of questionable reliability, because the information was available for only nine peritoneal cases.
  • The study was not designed to evaluate treatment.

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Asbestos Exposure, Autopsy, Occupational History, Asbestos Bodies, Pericardial, Pleural Effusion.

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