Re Ferrante et al (2020). Mortality and mesothelioma incidence among chrysotile asbestos miners in Balangero, Italy: A cohort study

Our plain-English summary of Re Ferrante et al (2020). Mortality and mesothelioma incidence among chrysotile asbestos miners in Balangero, Italy: A cohort study, by J. Schüz, H. Kromhout (American Journal of Industrial Medicine, 2020).

The study

• Authors: J. Schüz, H. Kromhout
• Journal: American Journal of Industrial Medicine
• Published: 2020;63(9):834-835
• Type of article: Letter, Comment
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

In plain English

This letter to the editor, not a new study, compared two analyses of the Balangero, Italy chrysotile miner cohort: Ferrante et al (2020) and Pira et al (2017). Cohort sizes were similar (974 versus 1056), but deaths were 573 versus 722 overall and 40 versus 53 from lung cancer. The letter called Ferrante et al's 1965 to 2013 SMR period the obvious, but incomplete, explanation. Lung cancer SMRs versus the general population were almost identical: 1.14 (95% CI 0.81 to 1.55) and 1.16 (0.87 to 1.52). By cumulative exposure (fiber/mL-years), Pira et al reported 0.82 (CI 0.44 to 1.40) below 100, 1.46 (0.89 to 2.26) for 100 to under 400, and 1.25 (0.76 to 1.93) for 400+, against an external reference. Ferrante et al, using below 27 as reference, reported 2.3 (0.8 to 6.8) for 27 to 345 and 2.6 (0.8 to 8.8) for 346+. For mesothelioma, Ferrante et al reported 6 pleural plus 2 peritoneal deaths and 6 incident cases; Pira et al, 7 pleural deaths. The writers asked Ferrante et al to reconcile the differences.

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: letter to the editor commenting on and comparing two published cohort analyses; no new data
• Who was studied: The letter discusses the Balangero, Italy chrysotile asbestos miner cohort as analyzed in two papers. Ferrante et al: 974 people and 35 362 person-years, follow-up to 31 May 2013. Pira et al: 1056 people and 37 471 person-years, follow-up to 31 December 2014.
• Exposure: chrysotile asbestos mining; cumulative dust exposure in fiber/mL-years, estimated from measurements from about 1969 onward and from simulations for earlier periods
• Main results:
  • Observed deaths differed between the papers: 573 overall deaths in Ferrante et al versus 722 in Pira et al, and 40 versus 53 lung cancer deaths.
  • The letter called it the obvious explanation that Ferrante et al presented SMRs only for 1965 to 2013 (21 175 person-years). It added that Ferrante et al's Poisson regression, said to cover the entire follow-up, listed only 41 lung cancer deaths, so additional explanation was still needed.
  • Overall lung cancer SMRs versus the general population were almost identical: 1.14 (95% CI 0.81 to 1.55) in Ferrante et al and 1.16 (CI 0.87 to 1.52) in Pira et al.
  • By cumulative exposure, Pira et al reported SMRs of 0.82 (CI 0.44 to 1.40), 1.46 (CI 0.89 to 2.26) and 1.25 (CI 0.76 to 1.93) for less than 100, 100 to less than 400, and 400+ fiber/mL-y, against an external reference. Ferrante et al used less than 27 fiber/mL-y as the reference category. They reported 2.3 (CI 0.8 to 6.8) for 27 to 345 and 2.6 (0.8 to 8.8) for 346+.
  • Ferrante et al reported a lung cancer SMR of 0.78 (CI 0.25 to 1.82) for its low-dose group compared with Piedmont reference rates. The letter said this did not fully explain the difference between the papers.
  • Mesothelioma data differed. Ferrante et al reported combined pleural and peritoneal malignancies: 6 + 2 deaths (1965 to 2013) and 6 incident cases (1990 to 2012). Pira et al reported 7 pleural deaths only.
  • The letter said it was unclear whether Ferrante et al's exposure assessment methods and data differed from the earlier assessment, or whether different cutoff points were used.
• The authors' conclusion: The letter writers asked Ferrante et al to explain and reconcile the differences between the two papers. They suggested harmonizing exposure categories and showing both within-cohort and external comparisons, for clarity and transparency.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Chrysotile, Cohort Study.

Related studies

• Mortality and mesothelioma incidence among chrysotile asbestos miners in Balangero, Italy: A cohort study — D. Ferrante, D. Mirabelli, et al. (2020)
• An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy — G. Piolatto, E. Negri, et al. (1990)
• An update of cancer mortality among chrysotile asbestos miners in Balangero, northern Italy — R. Calisti, P. De Giuli, et al. (1992)
• Mortality from cancer and other causes in the Balangero cohort of chrysotile asbestos miners — E. Pira, C. Pelucchi, et al. (2009)
• Cancer mortality in chrysotile miners and millers, Russian Federation: main results (Asbest Chrysotile Cohort-Study) — J. Schüz, E. Kovalevskiy, et al. (2024)
• Cancer mortality and incidence of mesothelioma in a cohort of wives of asbestos workers in Casale Monferrato, Italy — D. Ferrante, M. Bertolotti, et al. (2007)

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