Classics in Oncology: Asbestos exposure and neoplasia

Our plain-English summary of Classics in Oncology: Asbestos exposure and neoplasia, by I.J. Selikoff, J. Churg, E.C. Hammond (CA: A Cancer Journal for Clinicians, 1984).

The study

• Authors: I.J. Selikoff, J. Churg, E.C. Hammond
• Journal: CA: A Cancer Journal for Clinicians
• Published: 1984;34(1):48-56
• Type of article: Historical article
• Cited by: 13 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. 001670).

Abstract

Building trades insulation workers have relatively light, intermittent exposure to asbestos. Of 632 insulation workers, who entered the trade before 1943 and were traced through 1962, 45 died of cancer of the lung or pleura, whereas only 6.6 such deaths were expected. Three of the pleural tumors were mesotheliomas; there was also one peritoneal mesothelioma. Four mesotheliomas in a total of 255 deaths is an exceedingly high incidence for such a rare tumor. In addition, an unexpectedly large number of men died of cancer of the stomach, colon, or rectum (29 compared with 9.4 expected). Other cancers were not increased; 20.5 were expected, and 21 occurred. Twelve men died of asbestosis.

In plain English

This 1984 article reprints a 1964 JAMA paper. The authors studied 632 insulation workers in the New York and Newark, New Jersey, asbestos workers' union locals at the end of 1942. From January 1, 1943, through December 31, 1962, each man was counted only once 20 years had passed since his first asbestos exposure (8,737.5 man-years), and deaths were compared with those expected from US white male rates for the same age and period. Of the 632 men, 255 died. Lung or pleural cancer caused 45 deaths against 6.6 expected. Three were pleural tumors recorded as mesotheliomas; one further case suggested peritoneal mesothelioma. Stomach, colon or rectal cancer caused 29 deaths against 9.4 expected. Other cancers combined were not increased (21 against 20.5 expected). Twelve men died of asbestosis. The authors concluded that this exposure resulted in lung cancer at about six to seven times the expected rate, and that smoking could not account for it. They suggested a possible link with gastrointestinal cancer. They had not obtained the smoking habits of the men who died.

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: Mortality study of a union membership cohort: observed deaths compared with expected deaths calculated from US white male death rates, taking age and calendar period into account
• Who was studied: 632 men on the rolls of New York Local 12 and Newark, New Jersey, Local 32 of the insulation workers' union as of January 1, 1943, followed through December 31, 1962. Only time after 20 or more years since first exposure was counted, giving 8,737.5 man-years. 255 of the men died before January 1, 1963.
• Exposure: Insulation work (pipe covering) with intermittent exposure to materials containing limited amounts of asbestos, often 2 to 20 percent, under conditions ranging from very dusty to little dust; no fiber type is named
• Main results:
  • Total deaths among the asbestos workers were below expected in 1943 to 1947 (28 observed against 39.7 expected) and above expected later: 88 observed against 54.4 expected in 1958 to 1962
  • 45 of the 632 asbestos workers died of cancer of the lung or pleura, against 6.6 expected from US white male rates; 42 were recorded as bronchogenic carcinoma; the death rate was 6.8 times that of US white males
  • In 3 of the 255 deaths the examining pathologist considered the cause to be diffuse pleural mesothelioma; one further case suggested diffuse peritoneal mesothelioma, which the authors called too fragmentary for evaluation
  • 12 deaths from gastric cancer occurred among the asbestos workers, against 4.3 expected
  • 17 deaths from cancer of the colon and rectum occurred among the asbestos workers, against 5.2 expected; cancer of the stomach, colon and rectum together was three times as frequent as expected (29 against 9.4)
  • Cancer of all other sites combined was not increased among the asbestos workers: 21 deaths against 20.5 expected
  • 12 of the 255 deaths were due to asbestosis
  • Among the asbestosis deaths, the time from first asbestos exposure to death averaged 45.8 years, with a range of 32 to 59 years
  • The authors estimated that even if all the workers had been heavy cigarette smokers, the lung cancer death rate would have been about 3.4 times the general rate. They concluded that smoking could not account for the 6.8-fold rate.
• The authors' conclusion: The authors concluded that industrial asbestos exposure among these insulation workers resulted in a marked increase in lung cancer, about six to seven times the expected incidence. They wrote that the gastrointestinal findings suggest there may be an etiological relationship between asbestos exposure and gastrointestinal cancer.
• Limitations the authors state:
  • The smoking habits of the men who died had not been ascertained
  • The smoking survey of 320 of the 377 surviving members did not include the men who died or all living union members
  • The findings relate to the specific conditions of these insulation workers and would not necessarily apply to other industries such as asbestos product manufacturing or asbestos textiles
  • Histological verification of mesothelioma is uncertain; the authors could review the tissue in only two of the three pleural mesothelioma cases
  • Expected rates for 1958 to 1962 were projected from 1958 to 1960 because 1961 to 1962 rates were not yet available

Topics

Medical terms in this study, explained in our Lexicon: Asbestos Exposure, Insulator, Pleura, Mesothelioma, Peritoneal Mesothelioma, Stomach Cancer.

Related studies

• Cancer mortality in U.S. counties with shipyard industries during World War II — W.J. Blot, B.J. Stone, et al. (1979)
• Neoplasia among insulation workers in the United States with special reference to intra-abdominal neoplasia — E.C. Hammond, I.J. Selikoff, et al. (1965)
• Asbestos exposure and neoplasia — I.J. Selikoff, J. Churg, et al. (1964)
• Asbestosis and neoplasia — I.J. Selikoff, R.A. Bader, et al. (1967)
• Type of asbestos and respiratory cancer in the asbestos industry — P.E. Enterline, V. Henderson (1973)
• Malignant mesothelioma: a clinical study of 238 cases — S.E. Haber, J.M. Haber (2011)

Browse more research in CA: A Cancer Journal for Clinicians, or return to medical research.