Occupational exposure to dusts and risk of renal cell carcinoma

Our plain-English summary of Occupational exposure to dusts and risk of renal cell carcinoma, by S. Karami, P. Boffetta, P.S. Stewart, et al (British Journal of Cancer, 2011).

The study

• Authors: S. Karami, P. Boffetta, P.S. Stewart, P. Brennan, D. Zaridze, V. Matveev, V. Janout, H. Kollarova, V. Bencko, M. Navratilova, N. Szeszenia-Dabrowska, D. Mates, J. Gromiec, A. Slamova, W.H. Chow, N. Rothman, L.E. Moore
• Journal: British Journal of Cancer
• Published: 2011;104(11):1797-803
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Occupational exposures to dusts have generally been examined in relation to cancers of the respiratory system and have rarely been examined in relation to other cancers, such as renal cell carcinoma (RCC). Although previous epidemiological studies, though few, have shown certain dusts, such as asbestos, to increase renal cancer risk, the potential for other occupational dust exposures to cause kidney damage and/or cancer may exist. We investigated whether asbestos, as well as 20 other occupational dust exposures, were associated with RCC risk in a large European, multi-center, hospital-based renal case-control study.

Methods: General occupational histories and job-specific questionnaires were reviewed by occupational hygienists for subject-specific information. Odds ratios (ORs) and 95% confidence intervals (95% CIs) between RCC risk and exposures were calculated using unconditional logistic regression.

Results: Among participants ever exposed to dusts, significant associations were observed for glass fibres (OR: 2.1; 95% CI: 1.1-3.9), mineral wool fibres (OR: 2.5; 95% CI: 1.2-5.1), and brick dust (OR: 1.5; 95% CI: 1.0-2.4). Significant trends were also observed with exposure duration and cumulative exposure. No association between RCC risk and asbestos exposure was observed.

Conclusion: Results suggest that increased RCC risk may be associated with occupational exposure to specific types of dusts. Additional studies are needed to replicate and extend findings.

In plain English

This hospital-based case-control study compared 1097 people with newly diagnosed renal cell carcinoma, a kidney cancer, with 1476 hospital patients without it in Russia, Romania, Poland and the Czech Republic between 1999 and 2003. Experts reviewed job histories to judge exposure to asbestos and 20 other workplace dusts. Analyses used only exposures the experts rated probable or definite. In this analysis, 79 cases (9.7% of cases analysed) and 112 controls (9.5% of controls analysed) had asbestos exposure (odds ratio 0.8, 95% CI 0.5–1.2), and the authors found no association between asbestos and kidney cancer. Results for chrysotile (0.7; 0.4–1.2) and amphibole asbestos (1.4; 0.6–3.1) were also not statistically significant. Significantly higher odds were found for glass fibres (2.1; 1.1–3.9), mineral wool fibres (2.5; 1.2–5.1) and brick dust (1.5; 1.0–2.4), with significant trends by years of exposure. The fibre results were adjusted for asbestos. Most people exposed to mineral wool had also been exposed to asbestos. The authors concluded these possible associations need replication. They noted that chance findings among 63 tests were probable and that small exposed groups limited power for some analyses.

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: Hospital-based, multi-center case-control study (the Central and Eastern European Renal Cell Carcinoma, CEERCC, study). Experts assessed exposure from interview questionnaires. Analyses were restricted to exposures rated with high confidence (probable or definite), and odds ratios were calculated by unconditional logistic regression.
• Who was studied: 1097 newly diagnosed, histologically confirmed renal cell carcinoma cases and 1476 hospital controls, frequency-matched on age, sex and residence. They were recruited in Moscow (Russia), Bucharest (Romania), Lodz (Poland) and four Czech centres between 1999 and 2003.
• Exposure: Occupational exposure to asbestos (also analysed separately as chrysotile and amphibole asbestos) and 20 other dusts, including glass fibres, mineral wool fibres, brick dust, respirable free crystalline silica and wood dust. Experts rated exposure from lifetime job histories as ever exposure, duration and cumulative exposure. Analyses were restricted to probable or definite exposures.
• Main results:
  • Asbestos, ever exposed, in the high-confidence exposure analysis: 79 cases (9.7% of cases analysed) and 112 controls (9.5% of controls analysed) were exposed, giving an odds ratio of 0.8 (95% CI 0.5–1.2). The authors reported no association between asbestos and renal cell carcinoma risk.
  • Exposure analyses were limited to exposures assessed with high confidence, at least 40% (probable or definite).
  • Chrysotile asbestos, ever exposed: 43 cases and 75 controls were exposed, giving an odds ratio of 0.7 (95% CI 0.4–1.2).
  • Amphibole asbestos, ever exposed: 24 cases and 32 controls were exposed, giving an odds ratio of 1.4 (95% CI 0.6–3.1).
  • Asbestos and the other dusts listed were not associated with renal cell carcinoma risk by duration or cumulative exposure.
  • Increased odds ratios were found among those ever exposed to glass fibres (OR 2.1; 95% CI 1.1–3.9), mineral wool fibres (OR 2.5; 95% CI 1.2–5.1) and brick dust (OR 1.5; 95% CI 1.0–2.4).
  • The glass fibre and mineral wool fibre models were also adjusted for occupational asbestos exposure.
  • Longer duration of exposure was linked to a two- to three-fold increase in risk for glass fibres (trend p = 0.03), mineral wool fibres (trend p = 0.02) and brick dust (trend p = 0.01).
  • Among subjects exposed to mineral wool fibres, 86% of cases and 64% of controls had also been occupationally exposed to asbestos.
  • No association was observed between respirable free crystalline silica exposure and renal cell carcinoma risk (OR 1.0; 95% CI 0.7–1.5).
• The authors' conclusion: The authors concluded that their results showed a possible association between renal cell carcinoma risk and occupational exposure to glass fibre, mineral wool fibre and brick dust. They said these associations require replication, and that the lack of association with silica and asbestos justifies further investigation.
• Limitations the authors state:
  • Power for some exposure-response analyses was limited by small numbers of exposed subjects.
  • Recall of job histories may have been inaccurate or incomplete, and hospital-based controls may not represent the general population.
  • There were no data on protective equipment, ventilation, working conditions or environmental dust, which may have increased exposure misclassification.
  • Other risk factors, such as other occupational exposures, genetics and diet, were not considered, so uncontrolled confounding may have biased the results.
  • Of 63 tests performed, 11 were positive, and the authors considered chance findings from multiple comparisons probable.
  • The authors stated it is unclear whether the associations with glass and mineral wool fibres are real.

Topics

Medical terms in this study, explained in our Lexicon: Occupational Exposure, Carcinoma, Case-Control Study, Odds Ratio, confidence interval, Cumulative Exposure, Asbestos Exposure.

Related studies

• Occupational risk factors for renal cell carcinoma: agent-specific results from a case-control study in Germany. MURC Study Group. Multicenter urothelial and renal cancer study — B. Pesch, J. Haerting, et al. (2000)
• Occupational risk factors for renal cell cancer: a case--control study in northern Italy — S. Mattioli, D. Truffelli, et al. (2002)
• Case-control study on renal cell cancer and occupational exposure to trichloroethylene. Part I: Exposure assessment — J. Fevotte, B. Charbotel, et al. (2006)
• Renal cell carcinoma — P.A. Godley, M.A. Escobar (1998)
• The epidemiology of renal cell carcinoma — L. Lipworth, R.E. Tarone, et al. (2006)
• A comparative immunohistochemical study of malignant mesothelioma and renal cell carcinoma: the diagnostic utility of Leu-M1, Ber EP4, Tamm-Horsfall protein and thrombomodulin — R.L. Attanoos, H. Goddard, et al. (1995)

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