Part III: 7th Walter Hubert lecture. Pott and the prospects for prevention

Our plain-English summary of Part III: 7th Walter Hubert lecture. Pott and the prospects for prevention, by R. Doll (British Journal of Cancer, 1975).

The study

• Author: R. Doll
• Journal: British Journal of Cancer
• Published: 1975;32(2):263-72
• Type of article: Historical article
• Cited by: 21 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

In plain English

This article is the published text of the 7th Walter Hubert Lecture, given by the author on 8 April 1975. It was a historical review, not a new study. Marking 200 years since Percival Pott described scrotal cancer in chimney sweeps, it traced how occupational cancer hazards were discovered. Asbestos appeared among hazards found after 1915. The lecture's table linked it to cancer of the bronchus and to mesothelioma of the pleura and peritoneum. The lecture recounted earlier work by others: necropsy reports of lung cancer in people with asbestosis, an earlier 1955 study by the author of heavily exposed asbestos factory workers, and a South African series of 16 mesothelioma cases whose patients had all lived near an open asbestos mine in childhood. The author judged that laboratory results led to the discovery of only 4 occupational risks, and that epidemiological methods directly discovered only 4. The author concluded that the first priority was to detect human epidemics early, chiefly through industry records comparing workers' disease-specific death rates with those of the general population. The author added that alert clinicians would still be needed.

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: Published lecture: a historical review of how occupational cancer hazards were discovered, with proposals for prevention. No new data were collected.
• Who was studied: No study population. The lecture reviewed occupational cancer hazards recognised from Pott's 1775 description up to 1975. Table I covered hazards discovered before 1915. Table II covered hazards discovered since 1915, from which the author distinguished 19 risks.
• Exposure: Many occupational agents, including soot, tar, ionizing radiation, arsenic, aromatic amines, mustard gas, vinyl chloride, nickel, chromate and hardwood dust. Asbestos was listed for asbestos workers, insulation workers and dockyard workers, with sites given as pleura and peritoneum (mesothelioma) and bronchus. No fiber type was named.
• Main results:
  • The lecture recounted that Lynch and Smith (1935) reported a bronchial carcinoma at necropsy in a man with gross asbestosis. The author described this as a risk suggested by a single observation.
  • Merewether (1949), as cited in the lecture, reported lung cancer in 13.2% of necropsies on asbestotics (31 out of 235), compared with 1.3% of necropsies on silicotics (91 out of 6884).
  • Gloyne (1951), as cited in the lecture, reported corresponding figures of 14.1% and 6.9% in a large personal series.
  • The lecture cited the author's earlier 1955 study. In that study, men heavily exposed in an asbestos factory had 10 times the normal mortality from lung cancer over 30 years. The author wrote that this finally proved the relationship.
  • The lecture recounted that patients of Dr C. A. Sleggs at Kimberley Hospital were transferred to Johannesburg, where pleural biopsy led to the diagnosis of 16 cases of mesothelioma. The patients had varied occupations, but all had lived near an open asbestos mine in childhood.
  • Among the hazards discovered since 1915, the author judged that knowledge of laboratory results led to the discovery of only 4.
  • The author judged that only 4 hazards had been discovered directly by epidemiological methods. Most of the rest were first suspected by clinicians or pathologists.
• The authors' conclusion: The author concluded that the first priority was to detect human epidemics as early as possible. The author argued that periodic medical examination could not do this. Instead, industry should keep records allowing disease-specific mortality among process workers to be compared with the general population, including after the workers leave. The author also proposed better use of cancer registration and computer record linkage, and said alert clinicians would still be needed.
• Limitations the authors state:
  • The author stated that the division of post-1915 hazards into 19 separate risks was somewhat arbitrary.

Related studies

• A hazardous society? Individual versus community responsibility in cancer prevention. Third annual Matthew B. Rosenhaus Lecture — J. Higginson (1976)
• Dangerous and cancer-causing properties of products and chemicals in the oil refining and petrochemical industry: Part V--Asbestos-caused cancers and exposure of workers in the oil refining industry — M.A. Mehlman (1991)
• Prospects for cancer prevention — L.R. Ferguson (1999)
• 1987 H. P. Smith award lecture. Eyes for the epidemiologist: the pathologist's role in shaping our understanding of the asbestos-associated diseases — J.E. Craighead (1988)
• Assessing Tumor-Infiltrating Lymphocytes in Solid Tumors: A Practical Review for Pathologists and Proposal for a Standardized Method from the International Immuno-Oncology Biomarkers Working Group: Part 2: TILs in Melanoma, Gastrointestinal Tract Carcinomas, Non-Small Cell Lung Carcinoma and Mesothelioma, Endometrial and Ovarian Carcinomas, Squamous Cell Carcinoma of the Head and Neck, Genitourinary Carcinomas, and Primary Brain Tumors — S. Hendry, R. Salgado, et al. (2017)
• Update of the Texaco mortality study 1947-93: Part II. Analyses of specific causes of death for white men employed in refining, research, and petrochemicals — B.J. Divine, C.M. Hartman, et al. (1999)

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