Asbestos fiber burdens in lung tissues of Hong Kong Chinese with and without lung cancer

Our plain-English summary of Asbestos fiber burdens in lung tissues of Hong Kong Chinese with and without lung cancer, by Y. Liu, P. Zhang, F. Yi (Lung Cancer, 2001).

The study

• Authors: Y. Liu, P. Zhang, F. Yi
• Journal: Lung Cancer
• Published: 2001;32(2):113-6
• Cited by: 7 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

To investigate the asbestos exposure level in non-occupational population and its relation to lung cancer, pulmonary asbestos fiber counts were observed with a modified alkali digestion method, in lung tissues from 65 random surgically treated lung cancer patients (42 males and 23 females) and that obtained from 107 random autopsy cases who died of either accidental death or acute myocardial infarction (44 males and 63 females) during 1987-1988. The patients and cases were all Hong Kong Chinese with no definite history of occupational exposure to asbestos. The non-lung cancer cases (NLCC) were divided into three groups based on different age ranges: 10 approximately, 40 approximately and 70 approximately years. The results showed that the medians of uncoated fiber counts (0, 32 and 52 fibers per mg dry tissue [f/mgDT] in the different age groups, respectively) increased in an age-dependent manner (P<0.01). However, the medians of coated fiber (asbestos body) counts were all 0 f/mgDT, with no statistically significant difference among the groups, showing a very low level of asbestos body burden in NLCC. In each age group, no difference in those counts between males and females was observed (P>0.05). Moreover, those counts in male lung cancer cases (medians of 62.5 and 17.5 f/mgDT, respectively) were greater than that in the control (32.5 and 0 f/mgDT, respectively) (P<0.01, P<0.05, respectively), however, regarding the female groups there was no statistically significant difference from the control. The results suggest that there is an environmental exposure to asbestos in Hong Kong Chinese, the level of which is, however, generally not sufficient to induce asbestos body. Environmental asbestos exposure in Hong Kong males may be one of the carcinogenic factors leading to lung cancer.

In plain English

This study counted asbestos fibers in lung tissue from Hong Kong Chinese people with no definite history of work exposure to asbestos. Tissue came from 65 lung cancer patients (42 men, 23 women) who had surgery and 107 people autopsied after accidental death or acute myocardial infarction, in 1987 to 1988 in Hong Kong. The authors used light microscopy to count uncoated fibers and coated fibers (asbestos bodies) per milligram of dry lung tissue. Among the autopsy cases, median uncoated fiber counts were 0, 32 and 52 in the youngest, middle and oldest age groups, rising with age. Median asbestos body counts were 0 in all three groups. Men with lung cancer had higher medians than male controls: 62.5 versus 32.5 for uncoated fibers and 17.5 versus 0 for asbestos bodies. For women, the difference was not statistically significant. The authors concluded that Hong Kong Chinese had environmental asbestos exposure, generally too low to form asbestos bodies, and that in men it may be one factor leading to lung cancer. They noted that they lacked accurate smoking data and had few female lung cancer patients. Fiber types were not identified.

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: Comparison of lung-tissue asbestos fiber counts across age groups and between lung cancer patients (surgical tissue) and people without lung cancer (autopsy tissue), using light (phase-contrast) microscopy after alkali digestion
• Who was studied: Hong Kong Chinese studied in 1987 to 1988: 65 surgically treated lung cancer patients (42 males, 23 females) and 107 autopsy cases who died of accidental death or acute myocardial infarction (44 males, 63 females). For the sex-by-sex comparison with lung cancer cases, the controls were males older than 16 and females aged 21 to 80.
• Exposure: Non-occupational (environmental) asbestos exposure, measured as uncoated asbestos fibers and coated fibers (asbestos bodies) per mg dry lung tissue. Fiber types were not identified.
• Main results:
  • In non-lung cancer cases, median uncoated fiber counts were 0, 32 and 52 f/mgDT in the three age groups (labelled 10, 40 and 70 years), with each older group greater than the younger.
  • In non-lung cancer cases, median asbestos body (coated fiber) counts were 0 f/mgDT in all three age groups, with no statistically significant difference among them.
  • Within each age group of non-lung cancer cases, uncoated and coated fiber counts did not differ between males and females.
  • Male lung cancer cases had median uncoated and coated fiber counts of 62.5 and 17.5 f/mgDT. These were greater than in male controls (32.5 and 0 f/mgDT), reported as P less than 0.01 and P less than 0.05 respectively.
  • Female lung cancer cases did not differ statistically significantly from female controls.
  • Asbestos body counts were below the detectable limit (1 f/mgDT) in 64.3% of male and 60.5% of female controls. They were above it in 66.7% of male and 47.9% of female lung cancer cases.
  • Uncoated fiber counts above 100 f/mgDT occurred in 18.8% of controls and 29.2% of lung cancer cases (sexes combined). For asbestos body counts the figures were 4.7% and 3.1%.
• The authors' conclusion: The authors concluded that there is environmental asbestos exposure in Hong Kong Chinese, generally at a level not sufficient to induce asbestos bodies. In Hong Kong males it may be one of the carcinogenic factors leading to lung cancer; in females they considered a role less probable.
• Limitations the authors state:
  • The authors did not have accurate smoking data for the subjects.
  • The number of female lung cancer patients may have been too small.
  • Fiber types were not identified; the authors said this needs electron microscopy in future research.

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: Fiber Burden, Lung Cancer, Asbestos Exposure, Autopsy, Occupational Exposure, Asbestos Bodies, Environmental Exposure, Carcinogenic.

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