Cohort mortality study of women compensated for asbestosis in Italy

Our plain-English summary of Cohort mortality study of women compensated for asbestosis in Italy, by D. Germani, S. Belli, C. Bruno, et al (American Journal of Industrial Medicine, 1999).

The study

• Authors: D. Germani, S. Belli, C. Bruno, M. Grignoli, M. Nesti, R. Pirastu, P. Comba
• Journal: American Journal of Industrial Medicine
• Published: 1999;36(1):129-34
• Cited by: 39 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: The carcinogenic effect of asbestos is accepted for lung cancer and mesothelioma, while conflicting opinions exist for other cancer sites. The aim of the present investigation is to study cause-specific mortality of women compensated for asbestosis who had certainly been exposed to high levels of asbestos fibers.

Methods: The cause-specific mortality of all Italian women compensated for asbestosis and alive December 31, 1979, was investigated through October 30, 1997. In the total cohort, which included 631 subjects, 277 deaths occurred. Cause-specific SMRs (Standardized Mortality Ratio) were computed using the national rates for comparison.

Results: A significantly increased mortality for all diseases related to asbestos exposure was observed. Mortality for all causes, all neoplasms, lung cancer, uterine cancer, ovarian cancer, and non-neoplastic respiratory diseases was significantly increased. Separate analyses for textile (n = 276) and asbestos-cement (n = 278) workers were performed. Women employed in the textile industry, mainly exposed to chrysotile, who are compensated at a younger age, showed higher SMRs for lung cancer and asbestosis. Women in the asbestos-cement industry, mainly exposed to crocidolite containing asbestos mixtures, experienced higher mortality for pleural malignancies.

Conclusions: The role of asbestos exposure in the development of gastrointestinal and genital neoplasms is discussed.

In plain English

The authors followed all 631 Italian women compensated for asbestosis who were alive at the end of 1979, recorded deaths through 1997, and compared them with national death rates (standardized mortality ratios, or SMRs, where 100 means as expected). There were 277 deaths. Deaths from all causes (SMR 158) and all cancers (SMR 242) were significantly higher than expected. So were deaths from lung cancer (16 deaths), pleural cancer (14), peritoneal and retroperitoneal cancer (12), colon and sigmoid cancer (8), ovarian cancer (9) and uterine cancer (7). Thirty-eight women died of asbestosis, against almost none expected. Textile workers, mainly exposed to chrysotile, had a higher lung cancer SMR. Asbestos-cement workers, exposed to mixtures containing crocidolite, had more pleural cancer deaths (12 versus 2). The authors concluded that the lung, pleural and peritoneal excesses can be causally attributed to asbestos. They said the colon, ovary and uterus findings support a hypothesized role of asbestos. Smoking data were not available, and peritoneal mesothelioma is recorded with poor accuracy on death certificates.

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: Retrospective cohort mortality study comparing the cohort with national mortality rates using standardized mortality ratios (SMRs) with 95% confidence intervals
• Who was studied: 631 Italian women compensated for asbestosis by the National Institute for Insurance of Occupational Accidents (INAIL), alive at the end of 1979 and followed from January 1, 1980 to 1997. Subgroups were 276 textile-industry workers and 278 asbestos-cement workers. 277 women died and 4 were lost to follow-up.
• Exposure: Occupational asbestos exposure high enough to be compensated as asbestosis. Textile workers were mainly exposed to chrysotile. Asbestos-cement workers were mainly exposed to crocidolite-containing asbestos mixtures; the article describes these mixtures as about 40% asbestos with varying proportions of chrysotile and amphiboles.
• Main results:
  • Total cohort: 277 deaths from all causes, SMR 158 (95% CI 139 to 178)
  • Total cohort: 105 deaths from malignant neoplasms, SMR 242 (95% CI 198 to 293)
  • Total cohort: 16 lung cancer deaths, SMR 483 (95% CI 276 to 784)
  • Total cohort: 14 deaths from cancer of the pleura, SMR 6,404 (95% CI 3,503 to 10,749), according to Table II. The text gives 12 deaths.
  • Total cohort: 12 deaths from cancer of the peritoneum and retroperitoneum, SMR 4,094 (95% CI 2,116 to 7,152)
  • Total cohort: 8 deaths from colon and sigmoid cancer, SMR 238 (95% CI 103 to 470)
  • Total cohort: 9 ovarian cancer deaths, SMR 477 (95% CI 218 to 906)
  • Total cohort: 7 uterine cancer deaths, SMR 256 (95% CI 103 to 528)
  • Total cohort: 38 deaths from asbestosis, against an expected number the table gives as less than 0.01. The SMR for diseases of the respiratory system was 667.
  • Total cohort: mortality for diseases of the nervous system, circulatory system, and accidents was below expected
  • Lung cancer by industry: textile workers 9 deaths, SMR 682 (95% CI 312 to 1,295); asbestos-cement workers 4 deaths, SMR 239 (95% CI 66 to 613)
  • Pleural cancer by industry: textile workers 2 deaths, SMR 2,286 (95% CI 278 to 8,257); asbestos-cement workers 12 deaths, SMR 10,815 (95% CI 5,589 to 18,892)
  • Textile workers were compensated at a younger mean age (46.1 years) than asbestos-cement workers (52.2 years) and showed relatively higher SMRs for asbestosis and lung cancer
• The authors' conclusion: The authors concluded that the significant excesses of lung, pleural and peritoneal cancers can be causally attributed to asbestos exposure. They stated that the increased SMRs for sigmoid and colon, ovary and uterus cancers support the hypothesis that asbestos plays a carcinogenic role in gastrointestinal and genital cancers.
• Limitations the authors state:
  • Women may have been diagnosed with asbestosis by different criteria, because diagnostic standards changed over time
  • Individual exposure data were held in local INAIL offices and were not cross-checked when the cohort was listed
  • Asbestosis on death certificates may in some cases have been emphasized because of compensation requirements
  • Death certification of peritoneal mesothelioma is quite inaccurate and may be confused with other abdominal cancers, so increased SMRs for these sites should be regarded with caution
  • Smoking habits were not available for individuals, so smoking's part in the lung cancer excess, and possible confounding for other cancers, could not be addressed
  • The data do not distinguish cancer of the cervix from cancer of the uterine body

Topics

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

Medical terms in this study, explained in our Lexicon: Carcinogenic, Lung Cancer, Mesothelioma, standardized mortality ratio (SMR), Asbestos Exposure, Neoplasm, Ovarian Cancer, Asbestos-Cement.

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