Ingested asbestos in filtered beer, in addition to occupational exposure, as a causative factor in oesophageal adenocarcinoma

Our plain-English summary of Ingested asbestos in filtered beer, in addition to occupational exposure, as a causative factor in oesophageal adenocarcinoma, by R.C. Fitzgerald, J.M. Rhodes (British Journal of Cancer, 2019).

The study

• Authors: R.C. Fitzgerald, J.M. Rhodes
• Journal: British Journal of Cancer
• Published: 2019;120(12):1099-1104
• Type of article: Review
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Oesophageal adenocarcinoma has become much more common over the past 50 years, particularly in Britain, with an unexplained male to female ratio of > 4:1. Given the use of asbestos filtration in commercial brewing and reports of its unregulated use in British public houses in the 1970's to clear draught beer "slops", we have assessed the hypothesis that ingested asbestos could be a causative factor for this increased incidence. Importantly, occupational asbestos exposure increases the risk of adenocarcinoma but not squamous cell carcinoma of the oesophagus. The presence of asbestos fibres was consistently reported in filtered beverages including beers in the 1970s and asbestos bodies have been found in gastrointestinal tissue, particularly oesophageal tissue, at autopsy. There is no reported association between the intake of alcohol and oesophageal adenocarcinoma but studies would mostly have missed exposure from draught beer before 1980. Oesophageal adenocarcinoma has some molecular similarities to pleural mesothelioma, a condition that is largely due to inhalation of asbestos fibres, including predominant loss of tumour suppressor genes rather than an increase of classical oncogenic drivers. Trends in incidence of oesophageal adenocarcinoma and mesothelioma are similar, rising rapidly over the past 50 years but now plateauing. Asbestos ingestion, either from beer consumed before around 1980, or from occupational exposure, seems a plausible causative factor for oesophageal adenocarcinoma. If this is indeed the case, its incidence should fall back to a low baseline by around 2050.

In plain English

This perspective article reviewed published evidence for the authors' hypothesis that swallowed asbestos, from asbestos-filtered beer drunk before about 1980 or from work exposure, could help explain the rise in oesophageal adenocarcinoma, a cancer of the gullet, particularly among British men. No new data were collected. The authors cited a 1968 study of six bottled and canned beers that found what were thought to be chrysotile fibres, averaging around 5000 per pint. They also recounted one 1973 patient, a pub landlord, who described filtering leftover draught beer through an asbestos slurry. They cited studies, including a Dutch cohort of 58,279 men, linking work asbestos exposure to adenocarcinoma but not squamous cell carcinoma of the oesophagus. They also cited autopsy reports of asbestos bodies in oesophageal tissue, molecular similarities with pleural mesothelioma, and similar time trends for the two cancers. The authors concluded that ingested asbestos could plausibly be a significant factor and that, if so, UK incidence should fall to a low level by about 2050. They noted that the link with work exposure is relatively modest and that the molecular changes also occur in other cancers.

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: Perspective (review) article presenting a hypothesis, based on published literature and one anecdotal patient account; no new data collected
• Who was studied: No study population of its own. The authors reviewed published studies: beer and beverage fibre analyses, occupational cohorts (including the Netherlands Cohort Study of 58,279 men and a Swedish study), autopsy tissue studies, molecular studies of oesophageal adenocarcinoma and mesothelioma, and incidence and mortality trends in Britain and England. They also described one middle-aged male patient seen in London in 1973.
• Exposure: Ingested asbestos from filtered alcoholic drinks, particularly beer before about 1980, including filtering of draught beer 'slops' in British pubs, plus occupational asbestos exposure. The authors stated they could not be sure of the fibre type used in beer filtration but considered chrysotile the most likely.
• Main results:
  • A cited 1968 electron microscopy study of six samples of commercially bottled and canned beers found what were thought to be chrysotile asbestos fibres, at an average of around 5000 fibres per pint.
  • One patient's account (a publican in 1973) described adding an asbestos slurry to leftover draught beer and filtering it. This is a single anecdotal report.
  • In the cited Netherlands Cohort Study of 58,279 men followed for a mean of 17.3 years, occupational asbestos exposure was significantly associated with oesophageal adenocarcinoma but not with squamous cell carcinoma.
  • In that Netherlands study, for ever versus never highly exposed subjects, the hazard ratio for oesophageal adenocarcinoma was 2.52 (95% CI 1.01 to 6.26).
  • A cited earlier Swedish study reported an incidence rate ratio of 4.5 (95% CI 1.4 to 14.3) for occupational asbestos exposure and oesophageal adenocarcinoma, with no significant association for squamous cell carcinoma.
  • A cited 2016 meta-analysis of 20 cohort studies found occupational asbestos exposure associated with oesophageal cancer overall (SMR 1.24; 95% CI 1.13 to 1.38, P less than 0.001). It did not separate adenocarcinoma from squamous cell carcinoma.
  • A cited autopsy study of 26 male subjects over 40 years old found that those with the highest concentration of asbestos bodies in the lungs also had asbestos bodies particularly in the oesophagus (mean 15.5 per gram).
  • The authors described a molecular similarity: mesothelioma is considered a 'disease of gene loss', as has been appreciated for oesophageal adenocarcinoma.
  • The authors pointed to similar time trends for oesophageal adenocarcinoma and pleural mesothelioma.
  • The authors pointed to similar male predominance: about 4.2 to 1 for mesothelioma in Britain and 4.5 to 1 for oesophageal adenocarcinoma in England.
• The authors' conclusion: The authors concluded that it seems plausible that ingested asbestos fibres, particularly but not solely from beer consumed before 1980, could be a significant factor in the epidemic of oesophageal adenocarcinoma. If the hypothesis is correct, they expected incidence in the UK to fall back to a low background level by about 2050.
• Limitations the authors state:
  • The association between occupational asbestos exposure and oesophageal adenocarcinoma is relatively modest compared with that for pleural mesothelioma.
  • Many of the molecular changes compared also occur in epithelial cancers not known to be mainly caused by asbestos.
  • Precise genetic comparisons with mesothelioma are difficult because of limited data.
  • No systematic analysis of asbestos in oesophageal cancer tissue has been reported.
  • It is unclear whether differing national time trends relate to differing asbestos exposure.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Throat and laryngeal cancer.

Medical terms in this study, explained in our Lexicon: Occupational Exposure, Adenocarcinoma, Asbestos Exposure, Squamous Cell Carcinoma, Asbestos Bodies, Autopsy, Pleural Mesothelioma, Mesothelioma.

Related studies

• Occupational exposures and risk of oesophageal cancer by histological type: a case-control study in eastern Spain — M. Santibañez, J. Vioque, et al. (2008)
• Occupational exposures and risk of esophageal and gastric cardia cancers among male Swedish construction workers — C. Jansson, A.L. Johansson, et al. (2005)
• Workplace exposures and oesophageal cancer — M.E. Parent, J. Siemiatycki, et al. (2000)
• Occupational asbestos exposure and risk of esophageal, gastric and colorectal cancer in the prospective Netherlands Cohort Study — N.S. Offermans, R. Vermeulen, et al. (2014)
• Occupational Exposures and Esophageal Cancer: Prog Study — A. Gressier, G. Gourier, et al. (2022)
• Alcohol, smoking, and occupational factors in cancer of the larynx: a case-control study — W. Ahrens, K.H. Jöckel, et al. (1991)

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