Asbestosis and neoplasia

Our plain-English summary of Asbestosis and neoplasia, by I.J. Selikoff, R.A. Bader, M.E. Bader, et al (The American Journal of Medicine, 1967).

The study

• Authors: I.J. Selikoff, R.A. Bader, M.E. Bader, J. Churg, E.C. Hammond
• Journal: The American Journal of Medicine
• Published: 1967;42(4):487-96
• Type of article: Review
• Cited by: 99 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001491).

Summary of the article

This editorial addressed a prediction by Thomson that asbestos-induced neoplasms would rival cigarette-induced lung cancer. It noted that asbestos bodies were found in the lungs of at least one fourth of adults dying in urban areas. The authors reviewed published evidence and their own data, emphasizing the long latent period of asbestos disease. Among 1,117 asbestos insulation workers, chest X-ray abnormalities were found in 10.4% of those first exposed less than ten years before, 44.1% at 10-19 years, 72.8% at 20-29 years, and over 90% after more than thirty years. Among 56 consecutive patients with neoplasm of the lung or pleura, death from lung cancer did not occur less than twenty years after onset of exposure. Of 325 consecutive deaths among insulation workers (1943-1966), 17 (about 5%) were due to mesothelioma, against about 1 in 10,000 deaths in the general population. In Dresden, lung cancer deaths rose as deaths from severe asbestosis fell with improved industrial hygiene. Pleural calcification was rare within twenty years of first exposure (5 of 725 workers) but was present in more than half of workers after forty years. Stomach and colon cancers also appeared increased. The authors stressed that disease could progress after exposure ended and urged occupational histories covering work decades earlier. They projected that neoplasms from current asbestos use would not appear until the 1990s, and they called for better industrial hygiene and awareness of environmental contamination.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This 1967 editorial reviewed published evidence, including the authors' own studies, on the long delay between first exposure to asbestos and disease. It covered pulmonary asbestosis, lung cancer, pleural and peritoneal mesothelioma, other cancers, and pleural calcification. Among over 1,100 asbestos insulation workers, chest X-ray abnormalities were found in 10 per cent of those first exposed less than ten years before and in 44 per cent of those first exposed ten to nineteen years before. Among fifty-six consecutive patients with lung or pleural tumors studied by the authors, none died of lung cancer less than twenty years after exposure began. Of 325 consecutive deaths among insulation workers (1943 to 1966), seventeen were due to pleural or peritoneal mesothelioma. Only five of 725 insulation workers had visible pleural calcification within twenty years of first exposure. One man who worked four months as an asbestos weaver in 1935 later developed progressive fibrosis. The authors concluded that a careful history of work done decades earlier is essential, and that cancers linked to current asbestos use would not appear until the 1990s.

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: Editorial reviewing published literature on asbestos-related disease and its latency, drawing in part on the authors' own previously reported series and one case
• Who was studied: Mainly industrially exposed workers described in the literature. The authors' own data cited include over 1,100 United States asbestos insulation workers, fifty-six consecutive patients with lung or pleural tumors, 325 consecutive deaths among insulation workers (1943 to 1966), and one patient (R. K.)
• Exposure: Industrial asbestos exposure, chiefly insulation work, asbestos factory work and asbestos textile work. The fiber varieties are mentioned only as a possible factor, not studied separately. Environmental exposure is discussed but was not measured.
• Main results:
  • Asbestos insulation workers: chest X-ray abnormalities in 10 per cent of those first exposed less than ten years before and 44 per cent of those first exposed ten to nineteen years before. The figure was 72 per cent at twenty to twenty-nine years, and the authors give over 90 per cent for more than thirty years.
  • Insulation workers: shortness of breath (dyspnea) was recorded in twenty-eight of 379 men ten to nineteen years from onset of exposure, and in almost half of 121 men more than forty years from onset.
  • Fifty-six consecutive patients with lung or pleural tumors studied by the authors: death from lung cancer did not occur in less than twenty years from onset of exposure.
  • Of 325 consecutive deaths among asbestos insulation workers (1943 to 1966), seventeen were due to mesothelioma of the pleura or peritoneum (approximately 5 per cent). This compares with an estimated approximately 1 in 10,000 deaths in the general population.
  • Insulation workers: visible pleural calcification was found in only five of 725 workers within twenty years from onset of exposure. It was found in more than half of those with more than forty years since onset (57.9 per cent in Table II).
  • Case of patient R. K.: he worked as an asbestos weaver in a brake lining factory for four months in 1935, with no later exposure. Progressive fibrosis first became evident on X-rays in 1953, and pleural calcifications were present on later films.
• The authors' conclusion: The authors concluded that asbestos disease is rarely seen less than ten to twenty years after exposure begins. They stated that an occupational history covering work decades earlier is essential, and that cancers linked to current asbestos use would not be evident until the 1990s. They called for awareness of environmental contamination risks until it is known whether the prediction about urban air is right or wrong.
• Limitations the authors state:
  • The authors state it is not known whether the small amounts of asbestos inhaled from air pollution have an effect comparable to industrial exposure; the prediction of widespread neoplasia is an assumption.
  • The authors state there are no complete data on the effect of stopping exposure, because exposed groups who stopped have not been compared with those who continued.
  • The authors note that X-rays may miss early fibrosis, so clinical disease tends to be underestimated.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Asbestosis, Lung cancer.

Medical terms in this study, explained in our Lexicon: Neoplasm, Lung Cancer, Asbestos Bodies, Insulator, Chest X-Ray, Pleura, Mesothelioma, Industrial Hygiene.

Related studies

• Asbestos exposure and neoplasia — I.J. Selikoff, J. Churg, et al. (1964)
• Neoplasia among insulation workers in the United States with special reference to intra-abdominal neoplasia — E.C. Hammond, I.J. Selikoff, et al. (1965)
• Classics in Oncology: Asbestos exposure and neoplasia — I.J. Selikoff, J. Churg, et al. (1984)
• The occurrence of asbestosis among insulation workers in the United States — I.J. Selikoff, J. Churg, et al. (1965)
• Pulmonary function in asbestosis: serial tests in a long-term prospective study — M.E. Bader, R.A. Bader, et al. (1965)
• Asbestosis and abdominal neoplasms — E.E. Keal (1960)

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