Changing patterns of lung cancer in the United States

Our plain-English summary of Changing patterns of lung cancer in the United States, by W.J. Blot, J.F. Fraumeni (American Journal of Epidemiology, 1982).

The study

• Authors: W.J. Blot, J.F. Fraumeni
• Journal: American Journal of Epidemiology
• Published: 1982;115(5):664-73
• Cited by: 32 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001756).

Abstract

Although mortality from lung cancer increased throughout the United States during 1950-1975, the rate of change varied according to sex, race, and geographic sector. A pronounced shift in the geographic pattern of lung cancer was seen in white males. The elevation in rates in urban counties of the north in the 1950s faded over time and was not observed in the 1970s. The highest rates during 1970-1975 were in the south, both in rural and urban areas, particularly at younger ages. The sharpest rise in US mortality rates was reported among nonwhite males. Cohort analysis revealed that for males born before 1885 age-specific rates among whites exceeded those among nonwhites by nearly 50%, but for those born after 1915 a 50% excess was seen among nonwhites. Among nonwhite males the highest mortality in the 1970s occurred in urban areas of the south. Among females the rate of increase in lung cancer mortality was higher in the 1970s, but racial and geographic differences tended to be minor. Cigarette smoking accounts for a substantial part of the shifting patterns of lung cancer, but it is likely that other factors are involved, including industrial exposure (e.g., exposure to asbestos in shipyards during World War II) and possibly nutritional deficiencies and other determinants yet to be identified.

In plain English

This descriptive study tracked deaths from lung cancer across the United States from 1950 to 1975. It used national records of 1,100,000 lung cancer deaths and census figures to calculate rates by sex, race (white, nonwhite), region, county size and birth year. Among white males, the national age-adjusted rate rose from 24.6 per 100,000 in 1950-1954 to 58.6 in 1970-1975. Over the same years, high-rate areas shifted from parts of the northeast and south to mainly the south, including rural southern counties. Nonwhite male rates rose faster. For men born in the late 1800s, nonwhite rates were about two-thirds of white rates, but for those born around 1915 they were some 50 per cent higher. Female rates rose nationwide with little racial difference. This study did not measure asbestos exposure. Citing their own earlier case-control studies of World War II shipyard work, the authors concluded that at least part of the southern coastal excess is related to occupational exposures, particularly asbestos in ship construction and repair. They noted their smoking data were limited and that descriptive studies are not useful by themselves for judging causes.

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: Descriptive study of national lung cancer death records and census population data (no individual exposure information)
• Who was studied: 1,100,000 deaths attributed to lung cancer in the United States during 1950-1975, analyzed by sex and race (white, nonwhite). County-level maps covered white males in the 3056 counties of the contiguous United States.
• Exposure: No specific exposure was measured. Mortality was compared by sex, race, region (northeast, south, north central, far west), county population size and year-of-birth cohort. Asbestos exposure in World War II shipbuilding is discussed only through the authors' earlier case-control studies.
• Main results:
  • Among white males, the national age-adjusted lung cancer death rate was 58.6 per 100,000 in 1970-1975, 2.4 times the rate of 24.6 in 1950-1954.
  • Among white males, 16 per cent of northeastern counties had rates in the highest decile of all US counties in 1950-1954, compared with 2.3 per cent in 1970-1975.
  • By the 1970s, rates among white males in small southern counties (population under 25,000) had nearly equalled those in large northeastern counties (over 250,000). At all ages below 65, rates were higher in the rural south.
  • Nationwide, among males, age-specific rates for nonwhites were only two-thirds of those for whites in cohorts born in the late 1800s. They resembled white rates for those born around 1900 and surpassed them by some 50 per cent for those born around 1915.
  • Among nonwhite males, the highest mortality in the 1970s occurred in highly populated southern counties. In 1950-1954, their age-adjusted rates had been 40 per cent higher in northern urban counties than in southern urban counties.
  • Lung cancer mortality among females rose throughout the country, with a larger rate of increase in the 1970s than the 1950s. Age-adjusted rates for white and nonwhite females remained nearly equal.
• The authors' conclusion: The authors concluded that smoking explains much of the change, but that the geographic and racial shifts suggest other factors may play some role. Citing their earlier case-control studies of World War II shipyard employment, they stated that at least part of the southern coastal excess is related to occupational exposures, particularly asbestos in ship construction and repair.
• Limitations the authors state:
  • The authors stated that their smoking assessments were based on limited data, and that smoking patterns over time by age, sex, race and region could not be precisely chronicled.
  • The authors stated that descriptive studies like this are not useful by themselves for drawing inferences about the causes of cancer.
  • Smaller numbers of deaths prevented county-level maps for white females and for nonwhites of both sexes.
  • The authors noted that census under-counts among blacks could affect racial comparisons, though they found no evidence of a systematic shift over time.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer.

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

Related studies

• Recent geographic patterns of lung cancer and mesothelioma mortality rates in 49 shipyard counties in the United States, 1970-94 — A. Jemal, D. Grauman, et al. (2000)
• Mesothelioma from asbestos exposures: Epidemiologic patterns and impact in the United States — R.A. Lemen (2016)
• Patterns of care and survival among patients with malignant mesothelioma in the United States — L. Enewold, E. Sharon, et al. (2017)
• Comment on "Mesothelioma from asbestos exposures: Epidemiologic patterns and impact in the United States" by R A Lemen, Journal of Toxicology and Environmental Health, Part B 2016;19:250-265 — C. Magnani, D. Mirabelli, et al. (2017)
• Author's response to: "Letter to the Editor" regarding content of "Mesothelioma from asbestos exposures: Epidemiologic patterns and impact in the United States" by R. A. Lemen, Journal of Toxicology and Environmental Health, Part B 2016; 19: 250-265 — (2017)
• Mesothelioma in the United States: a Surveillance, Epidemiology, and End Results (SEER)-Medicare investigation of treatment patterns and overall survival — J.L. Beebe-Dimmer, J.P. Fryzek, et al. (2016)

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