Histologic Type of Lung Cancer in Relation to Smoking Habits, Year of Diagnosis and Sites of Metastases

Our plain-English summary of Histologic Type of Lung Cancer in Relation to Smoking Habits, Year of Diagnosis and Sites of Metastases, by O. Auerbach, L. Garfinkel, V.R. Parks (1975).

The study

• Authors: O. Auerbach, L. Garfinkel, V.R. Parks
• Published: Chest, Volume 67 No4. April 1975
• 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 study concerned smoking and lung cancer type, not asbestos. The authors reviewed autopsies of 662 men who died of primary lung cancer at the Veterans Administration Hospital in East Orange, New Jersey, between 1955 and 1972. Trained interviewers took smoking histories from relatives. Of the cases, 35.2 percent were epidermoid carcinoma, 24.6 percent small cell carcinoma, 25.2 percent adenocarcinoma and 14.2 percent large cell undifferentiated carcinoma. All six men who had never smoked had adenocarcinoma. The share of small cell carcinoma fell over the years, but differences by year were not statistically significant. Overall, adjusted for age, the share of small cell carcinoma rose with cigarette smoking. Among men aged 70 or older it fell. Metastases were found in 96.3 percent of all 662 cases. Regional lymph nodes were involved most often, in 89.1 percent of the autopsies in which they were examined. Small cell carcinoma generally showed the highest metastasis percentages and epidermoid carcinoma the lowest. The authors concluded that no consistent trends by smoking habit, year of diagnosis or age group were observed. They noted that small metastases may be missed at autopsy.

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: autopsy case series; one pathologist reviewed the lung tissue slides twice in random order and classified tumor type by the WHO system
• Who was studied: 662 men who died of primary lung cancer and had usable smoking and residence histories, out of 1,003 lung cancer deaths found at autopsy, Veterans Administration Hospital, East Orange, New Jersey, 1955 to 1972
• Exposure: tobacco smoking: never-smokers, ex-cigarette smokers, and current cigarette smokers of less than 1, 1 to 2, and more than 2 packs a day, as reported by relatives; asbestos was not studied
• Main results:
  • Among all 662 cases: 35.2 percent epidermoid carcinoma, 24.6 percent small cell carcinoma, 25.2 percent adenocarcinoma, 14.2 percent large cell undifferentiated carcinoma
  • All six men who had never smoked had adenocarcinoma
  • Small cell carcinoma decreased in proportion over the study years, but differences by year of diagnosis were not statistically significant
  • Adjusted for age, the percentage of small cell carcinoma increased with cigarette smoking and was lowest among former smokers
  • Among men aged 70 or older, the percentage of small cell carcinoma decreased with more smoking
  • Epidermoid carcinoma increased with age and adenocarcinoma tended to decrease with age
  • Metastases were found in 96.3 percent of the 662 cases
  • Site-specific metastasis percentages were based only on the autopsies in which that organ was examined, not on all 662 cases
  • Metastases were found in 161 of 163 small cell carcinoma cases (99.4 percent), and in 94.0 percent of epidermoid, 96.4 percent of adenocarcinoma and 96.8 percent of large cell undifferentiated cases
  • The most frequent metastasis site was the regional lymph nodes (89.1 percent). Next came brain (44.7 percent), distant lymph nodes (44.6 percent) and liver (44.1 percent). Each percentage is of the autopsies in which that site was examined.
  • For the major sites, small cell carcinoma generally had the highest and epidermoid carcinoma the lowest percentage of metastases. These differences were statistically significant by chi-square test. Differences for brain were not statistically significant
  • The two slide readings agreed completely in 91.2 percent of the 662 pairs
• The authors' conclusion: The authors concluded that no consistent trends in tumor type by smoking habit, year of diagnosis or age group were observed. They also reported finding the pattern in which small cell carcinomas metastasize most and epidermoid carcinomas least.
• Limitations the authors state:
  • How completely metastasis sites were counted depends on the extent of the autopsy and the tissue sampled. Small metastases in large organs may be missed, and bone is not regularly examined extensively.
  • Not every organ was examined in every autopsy; for example, the brain was not examined in 116 of the 662 autopsies
  • Pipe and cigar smokers (19) and men with other tobacco habits (26) were too few to analyze separately

Topics

Medical terms in this study, explained in our Lexicon: Lung Cancer, Habit, Carcinoma, Adenocarcinoma, Metastasis, Autopsy.

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