Changes in Bronchial Epithelium in Relation to Smoking and Cancer of the Lung - Acta

Our plain-English summary of Changes in Bronchial Epithelium in Relation to Smoking and Cancer of the Lung - Acta, by O. Auerbach, J.B. Gere, J.B. Forman, et al (1964).

The study

• Authors: O. Auerbach, J.B. Gere, J.B. Forman, T.G. Petrick, H.J. Smolin, G.E. Muehsam, D.Y. Kassouny, A.P. Stout
• Published: Acta - Unio internationalis Contra Cancrum (International Union Against Cancer) (1964)
• 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 article does not concern asbestos. It reported a microscopic study of the windpipe and bronchial airways (the tracheobronchial tree) of 117 people who had died. Each was cut into 208 serial sections and examined for basal-cell hyperplasia, stratification, squamous metaplasia and carcinoma in situ. Of the 117, 34 had died of bronchogenic carcinoma. The non-lung-cancer group included 16 nonsmokers, 20 who smoked less than one pack a day and 47 who smoked more. Definite carcinoma in situ was found in 1.0 per cent of slides for nonsmokers, 4.1 per cent for under a pack a day, 6.0 per cent for over a pack a day, and 6.8 per cent for the lung-cancer group. The authors reported that these changes bore a direct relationship to cigarette consumption. An extension examined 54 patients who died of lung cancer. In these 54, definite or borderline carcinoma in situ appeared in 48 (89 per cent), including in the lung opposite the tumor, and early invasive cancer appeared in 5. The authors concluded that their findings were fully consistent with the hypothesis that inhaling tobacco smoke is an important factor in causing bronchogenic carcinoma.

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: Microscopic (histological) study of tracheobronchial trees from people who had died. Groups were compared by cause of death and smoking habit. The study continued earlier reports from the same institution.
• Who was studied: 117 cases, of whom 34 died of bronchogenic carcinoma. The non-lung-cancer group was made up of 16 nonsmokers, 20 who smoked less than one pack a day, and 47 who smoked more than one pack a day. As an extension, a similar study was made of 54 patients who died of lung carcinoma; the article does not say whether these overlapped with the 117. The affiliation was a Veterans Administration hospital laboratory service. The address is garbled in the scan, and no dates are given.
• Exposure: Tobacco smoking, mainly cigarettes, grouped by packs per day. In the lung-cancer group, 19 had smoked more than one pack a day, 10 less than one pack a day, four were ex-cigarette smokers, and one had smoked a pipe and cigars but no cigarettes. No asbestos exposure was studied.
• Main results:
  • Definite carcinoma in situ, as a percentage of slides examined. In the non-lung-cancer group: nonsmokers 1.0 per cent, less than one pack a day 4.1 per cent, more than one pack a day 6.0 per cent. In the lung-cancer group: 6.8 per cent.
  • Squamous metaplasia, as a percentage of slides. In the non-cancer group: nonsmokers 1.9 per cent, less than one pack 6.3 per cent, more than one pack 9.5 per cent. In the lung-cancer group the figure is printed as 1.7 per cent.
  • Stratification in the non-lung-cancer group: nonsmokers 4.2 per cent, less than one pack a day 7.1 per cent. The figures for more than one pack a day and for the lung-cancer group are printed as '104' and '134' per cent, which appears to be scanning damage.
  • Basal-cell hyperplasia in the non-cancer group: the nonsmoker figure is printed as '1R.6' per cent, less than one pack a day 22 per cent, and the figure for more than one pack a day is printed as '361' per cent. In the lung-cancer group: 43.5 per cent.
  • The authors stated that the frequency of these epithelial changes, including carcinoma in situ, bore a direct relationship to cigarette consumption
  • In the 54 lung-cancer patients, definite or borderline carcinoma in situ occurred in 17 per cent of 7993 usable slides, and in 48 of the 54 cases (89 per cent)
  • In the 54 lung-cancer patients, carcinoma in situ was found at a comparable frequency in the lung opposite the one with the overt cancer
  • Early invasive carcinoma was seen in 5 of the 54 lung-cancer cases, in areas showing carcinoma in situ. The authors took this as suggesting that carcinoma in situ is a stage before invasive cancer.
• The authors' conclusion: The authors concluded that their findings were fully consistent with the hypothesis that inhalation of tobacco smoke is an important factor in the causation of bronchogenic carcinoma
• Limitations the authors state:
  • The authors noted that other factors had been considered as possible causes of these changes, but this study examined only the relationship to tobacco consumption

Topics

Medical terms in this study, explained in our Lexicon: Epithelium, Carcinoma, Bronchogenic Carcinoma, Lung Cancer.

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