Appearance of the First Roentgenographic Abnormalities Due to Lung Cancer

Our plain-English summary of Appearance of the First Roentgenographic Abnormalities Due to Lung Cancer, by K.R. Boucot, D. Cooper, W. Weiss (1964).

The study

• Authors: K.R. Boucot, D. Cooper, W. Weiss
• Published: JAMA 190(13):77-80, December 28. (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 was a ten-year prospective study, the Philadelphia Pulmonary Neoplasm Research Project. It followed 6,137 male volunteers aged 45 or older, not a random sample, with chest X-ray films and symptom questionnaires every six months for eight to ten years. Seventy-six new lung cancers developed, all in smokers. In 45 cases the cancer appeared within nine months of a normal film. Of these, 27 arose in the outer lung, 9 of them as solitary nodules, and 17 arose centrally, all but one beginning with abnormalities at the lung root (hilum). More than half of the 76 cancers arose in men whose earlier films were abnormal. Eighteen of the 76 had lung scarring (fibrosis) beforehand. Two of the six proved cases of widespread fibrosis were asbestosis. Fibrosis was about as common in matched smokers without cancer and less common in matched nonsmokers. Seven men had pleural disease before cancer. The authors concluded that the first X-ray signs of lung cancer are highly variable, and that any new lung abnormality in older men should be suspected of being cancer unless another diagnosis is proved.

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: Prospective study (the Philadelphia Pulmonary Neoplasm Research Project) using X-ray films and symptom questionnaires every six months. Men who developed cancer were compared with matched samples of smokers and of nonsmokers without cancer.
• Who was studied: 6,137 male volunteers aged 45 years or more in Philadelphia, not a random sample. The study began in December 1951, and the men joined over a four-year period.
• Exposure: Mainly cigarette and cigar smoking and earlier abnormalities on the X-ray films. Occupational dust was not studied systematically. One case described was a lamp bagger in a plant that processed magnesium silicate; he had asbestosis as well as lung cancer at autopsy. No asbestos fiber types are named.
• Main results:
  • Of the 45 cancers that appeared within nine months of a normal film, 27 arose in the outer (peripheral) lung and 9 began as solitary nodules.
  • Among the 27 peripheral cancers, 9 were solitary nodules, 5 were frank masses, 1 was a uniform irregular density, and 12 began as small, irregular, uneven shadows (infiltrates).
  • Of the 17 cancers that arose centrally, all but one began with abnormalities at the lung root (hilum).
  • All 76 men who developed new cancer were smokers.
  • More than half of the 76 cancers arose in men whose earlier films showed abnormalities of the lungs or pleura.
  • Eighteen of the 76 men with new cancer had lung scarring (pulmonary fibrosis) before the cancer appeared: 9 localized and 9 widespread.
  • Six of the widespread fibrosis cases were proved by tissue examination: two were asbestosis, two silicosis and two nonspecific fibrosis.
  • Earlier fibrosis was found in about 24% of smokers with cancer, about 24% of matched smokers without cancer, and about 13% of matched nonsmokers. The scanned text prints these figures in damaged form; 24% matches 18 of 76.
  • Seven men had pleural disease before the cancer appeared.
  • Two film readers read the films at the time in 27 of the 45 cases. In only 15 of these did both readers recognize the first evidence of cancer.
• The authors' conclusion: The authors concluded that the first X-ray abnormalities due to lung cancer are highly variable and often not distinctive. Any abnormality appearing for the first time in the lungs of older men should be suspected of being lung cancer unless another diagnosis is proved.
• Limitations the authors state:
  • The men were volunteers, not a random sample.
  • Follow-up problems (illness, weather, loss of interest, clerical errors) made it very difficult to keep every man on a strict six-month schedule. Only 45 of the 76 cancers came within nine months of a previous visit.

Topics

Medical terms in this study, explained in our Lexicon: Lung Cancer, Neoplasm, Chest X-Ray, Hilum, Fibrosis.

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