The Role of Carcinogens, Especially Those in Cigarette Smoke, in the Production of Precancerous Lesions

This chapter, from the book Cancer of the Lung, does not mention asbestos. The authors, at the Veterans Administration Hospital in East Orange, New Jersey, described three continuing studies over 5 years of microscopic changes in the lining of the airways (the tracheobronchial tree). They compared people who died of lung cancer with people who died of other causes and had verified smoking histories. The lining in lung cancer cases showed all stages of precancerous change up to invasive cancer. Among people who died of other causes, nonsmokers had the fewest changes, and changes increased with the amount smoked. In the final study, no carcinoma in situ (early cancer confined to the lining) was found in nonsmokers or occasional smokers. It appeared on 0.3 per cent of slides from those smoking under half a pack a day, 11.4 per cent from those smoking two packs or more, and 15.0 per cent from lung cancer cases. All 23 early invasions arose at a carcinoma in situ. The authors concluded that cigarette smoke contains the single most important inhaled carcinogen.

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.

From J-M's medical library

This copy comes from the Johns-Manville medical library. It was among the papers J-M kept in its medical library without an index entry.

We publish pages from a book for research and commentary: it shows what the medical literature in a leading asbestos company's own library said on the subject, and when. Our summary above is our own reading of it. The copyright stays with the publisher.