The Value of Long-Term Testing for the Implementation of Primary Prevention

Our plain-English summary of The Value of Long-Term Testing for the Implementation of Primary Prevention, by L. Tomatis.

The study

• Author: L. Tomatis
• Published: n.d.
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This paper by L. Tomatis was a review and commentary on whether long-term animal cancer tests help prevent cancer in people. It was not a study of asbestos. Asbestos appeared only once, in a badly scanned passage that seems to name asbestos and cigarette smoking as the best-known human example of different causes having an additive effect. The author used diethylstilbestrol, 4-aminobiphenyl, vinyl chloride, 2-naphthylamine, bis(chloromethyl) ether and polychlorinated biphenyls as examples. They showed that animal evidence was in some cases preceded by human observations and in others quickly confirmed by them. The paper reported that the monographs of the International Agency for Research on Cancer (IARC) had covered 296 chemicals. For 21 of them, a link with cancer in humans was established or strongly suspected, and exposure was solely or mainly occupational for 14 of these. For 144, animal evidence in at least one species was judged adequate. The author also reviewed surveys on mouse liver tumors and on injection under the skin as test methods. A survey of cancer-prevention laws in 14 industrialized countries found that only 4 banned both import and manufacture of chemical carcinogens. The author concluded that animal evidence gives enough warning to start preventive measures.

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: Review and commentary on the value of long-term animal carcinogenicity testing for primary cancer prevention. It draws on IARC monographs and on surveys by the author and colleagues of testing laboratories, of test methods, and of national legislation.
• Who was studied: No human study population. The paper reviewed chemicals evaluated in IARC monographs (296 chemicals), laboratories doing long-term testing (89 institutes in 19 countries, per a 1975 questionnaire), and cancer-prevention legislation in 14 industrialized countries.
• Exposure: Chemical carcinogens in general, with worked examples: diethylstilbestrol, 4-aminobiphenyl, vinyl chloride, 2-naphthylamine, bis(chloromethyl) ether and polychlorinated biphenyls. Asbestos is not a subject of the paper and is mentioned only in passing.
• Main results:
  • In a badly scanned passage on different causes of cancer having an additive effect, asbestos and cigarette smoking appear to be named as the best-known example in humans. This is a passing mention, not an asbestos study.
  • The six example chemicals were given to illustrate that experimental evidence was in some cases preceded by human observations and in others quickly confirmed by them.
  • Of the 296 chemicals in the IARC monographs, 21 had an association with cancer in humans that was established or strongly suspected.
  • For 14 of those 21 chemicals, exposure was solely or mainly occupational.
  • For 144 of the 296 chemicals, experimental evidence of carcinogenicity in at least one animal species was considered adequate.
  • The manufacture of 4-aminobiphenyl was never begun in the United Kingdom because of experimental evidence of carcinogenicity.
  • From the available information, the author judged the induction of liver tumors in mice to be an acceptable index of carcinogenicity.
  • Injection under the skin (subcutaneous route) produced, in most cases, results qualitatively similar to those from other routes of administration.
  • In only 4 of the 14 countries surveyed were both the importation and the manufacture of chemical carcinogens prohibited.
  • Most of the 14 countries recognized only a limited right to compensation for occupational cancer.
  • Some chemicals associated with cancer in humans, for example benzene and chromates, were left out of the lists of prohibited or controlled substances and were still produced on a large scale.
• The authors' conclusion: The author concluded that experimental evidence provides sufficient warning to prompt preventive measures. The author also concluded that legislation gives much more attention to a limited right to compensation than to enforcing primary prevention, and that agreement is badly needed on the validity of experimental results.
• Limitations the authors state:
  • In the IARC survey of testing laboratories, most commercial or industry-owned laboratories did not supply comprehensive information, so the data refer mainly to noncommercial laboratories.

Topics

Medical terms in this study, explained in our Lexicon: IARC.

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