Cancer mortality and wood dust exposure among participants in the American Cancer Society Cancer Prevention Study-II (CPS-II)

Our plain-English summary of Cancer mortality and wood dust exposure among participants in the American Cancer Society Cancer Prevention Study-II (CPS-II), by S.D. Stellman, P.A. Demers, D. Colin, et al (American Journal of Industrial Medicine, 1998).

The study

• Authors: S.D. Stellman, P.A. Demers, D. Colin, P. Boffetta
• Journal: American Journal of Industrial Medicine
• Published: 1998;34(3):229-37
• Cited by: 50 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

In 1994, the International Agency for Research on Cancer (IARC) classified wood duct as a human carcinogen, based on very strong evidence of a carcinogenic risk of sino-nasal cancer. Excesses of other cancers, including lung and stomach, have been reported among persons employed in wood industries or occupationally exposed to wood dust, but not as consistently. We investigated such possible associations using the mortality experience of 362,823 men enrolled in the American Cancer Society's Cancer Prevention Study-II in 1982 and followed up for 6 years. Within this group, 45,399 men (12.5%) reported either employment in a wood-related occupation or exposure to wood dust or both. Among woodworkers, a small but significant excess risk was found for all cases of death (RR 1.17 (95% CI 1.11-1.24)) and for total malignancies (RR 1.17 (1.05-1.30)). Among men who reported exposure to wood dust, there was an elevated risk of total mortality (Rr 1.07 (1.03-1.11)), total malignancies (RR 1.08 (1.01-1.15)), and lung cancer (RR 1.17 (1.04-1.31)). Among woodworkers, a significant trend (P = 0.02) of increasing risk of lung cancer with increasing duration of exposure was observed. An unexpected, significantly increased mortality from prostate cancer was observed in both wood-employed and wood-exposed, and a twofold increased risk of fatal brain cancer was seen among the former. Lung cancer mortality was especially high among woodworkers who also reported exposure to asbestos or formaldehyde, and it appears that exposure to these known carcinogens may partly explain the observed increased risks. Excess sino-nasal cancer was not observed, but the number of cases was small.

In plain English

This prospective cohort study followed 362,823 U.S. men enrolled in the American Cancer Society's Cancer Prevention Study II in 1982 for up to 6 years, looking at cancer deaths. Men were grouped as woodworkers (a wood-related job as current, last or longest-held job) or as reporting regular wood dust exposure. 45,399 were in one or both groups. Results were adjusted for age and smoking. Woodworkers had relative risks of 1.17 (95% CI 1.11–1.24) for death from all causes and 1.17 (1.05–1.30) for all cancers. Men reporting wood dust exposure had a lung cancer relative risk of 1.17 (1.04–1.31). Woodworkers who also reported asbestos exposure had a lung cancer relative risk of 2.25 (1.52–3.33), based on 25 deaths. Woodworkers also had excesses of prostate cancer and brain tumor deaths, sites not chosen in advance. Pleural neoplasms among woodworkers rested on only 2 deaths (RR 2.51, 0.57–10.9). No sino-nasal cancer excess was seen, though cases were few. The authors concluded that the woodworkers' lung cancer excess appeared associated not only with wood dust but also with asbestos and formaldehyde exposure.

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: prospective cohort study (mortality follow-up of a large volunteer-enrolled cohort, with an internal unexposed comparison group)
• Who was studied: 362,823 men from the American Cancer Society's Cancer Prevention Study II, enrolled in 1982 across all 50 U.S. states, the District of Columbia and Puerto Rico, and followed for up to 6 years (through August 1988). Of these, 45,399 (12.5%) reported a wood-related occupation, wood dust exposure, or both. The comparison group was 317,424 men with neither.
• Exposure: Two overlapping groups: woodworkers (carpenter, lumber worker, furniture maker/repairer/finisher, logger, sawmill operative, woodworker or woodcutter as current, last or longest-held job) and men self-reporting regular wood dust exposure on a checklist. Self-reported exposure to asbestos (fiber type not stated) and formaldehyde was also examined. Among woodworkers, 1,480 (13%) reported asbestos exposure and 387 (3%) formaldehyde exposure. The authors noted that work as a carpenter might explain asbestos exposure.
• Main results:
  • Woodworkers: all causes of death RR 1.17 (95% CI 1.11–1.24) and all malignant neoplasms RR 1.17 (1.05–1.30). Men reporting wood dust exposure: all causes RR 1.07 (1.03–1.11) and all malignant neoplasms RR 1.08 (1.01–1.15).
  • Lung cancer: RR 1.17 (1.04–1.31) among men reporting wood dust exposure (317 deaths). Among woodworkers the RR was 1.14 (0.94–1.37) (111 deaths).
  • Among woodworkers, lung cancer risk rose with duration of wood dust exposure (trend P = 0.02): RR 0.70 (0.26–1.88) for less than 10 years, 1.25 (0.62–2.50) for 10 to 19 years, and 1.45 (1.07–1.96) for 20 or more years.
  • Woodworkers who reported asbestos exposure: all cancers RR 1.60 (1.23–2.07) (57 deaths) and lung cancer RR 2.25 (1.52–3.33) (25 deaths). Among non-woodworkers reporting asbestos exposure, lung cancer RR was 1.17 (0.99–1.38) (86 deaths).
  • Woodworkers who reported formaldehyde exposure: lung cancer RR 2.63 (1.25–5.51), based on 7 deaths.
  • When the analysis was restricted to men with both asbestos and wood dust information, lung cancer RR among woodworkers reporting wood dust exposure was 1.33 (0.99–1.80) before and 1.27 (0.94–1.72) after adjusting for asbestos. Among non-woodworkers reporting wood dust exposure, it was 1.15 (0.97–1.33) before and 1.09 (0.94–1.27) after.
  • Pleural neoplasms: 2 deaths among woodworkers, RR 2.51 (0.57–10.9), and 3 deaths among men reporting wood dust exposure, RR 1.43 (0.42–4.87). The authors said the woodworker excess, though based on small numbers, is consistent with asbestos exposure.
  • Cancers not of prior interest: prostate cancer RR 1.23 (1.00–1.50) among men reporting wood dust exposure and 1.49 (1.14–1.95) among woodworkers. Brain tumors RR 2.02 (1.25–3.27) among woodworkers (18 deaths).
  • No excess sino-nasal cancer: 0 deaths among woodworkers, and 1 death among men reporting wood dust exposure (RR 1.05, 0.13–8.39).
  • After excluding men who said they were sick when they enrolled, lung cancer risk among men reporting wood dust exposure alone was not elevated (RR 1.00, 0.86–1.17). Among men reporting both wood dust exposure and a woodworking job, it was 1.19 (0.89–1.60).
• The authors' conclusion: The authors concluded that the excess of lung cancer among woodworkers appeared to be associated not only with wood dust but also with exposure to asbestos and formaldehyde. They found no other convincing associations with common cancers.
• Limitations the authors state:
  • Work history covered only the current, last and longest-held jobs.
  • Work history lacked details of the specific woodworking job and the industry of employment.
  • Exposures, including asbestos, were self-reported on a checklist and may have been misclassified. Only 55% of woodworkers reported regular wood dust exposure.
  • Recall bias may have affected self-reported exposures, particularly asbestos.
  • Follow-up was relatively short and death was the endpoint, so some participants were likely already diagnosed when they filled out the questionnaire.
  • The study had limited power for rare cancers, and small numbers prevented detailed analysis of formaldehyde.

Topics

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

Related studies

• Nonmalignant respiratory disease mortality among woodworkers participating in the American Cancer Society Cancer Prevention Study-II (CPS-II) — P.A. Demers, S.D. Stellman, et al. (1998)
• Occupational exposure to wood dust and risk of lung cancer: the ICARE study — M. Matrat, L. Radoï, et al. (2019)
• Extended mortality follow-up among men and women in a U.S. furniture workers union — B.A. Miller, A. Blair, et al. (1994)
• Cancer mortality among woodworkers — S.D. Stellman, L. Garfinkel (1984)
• A case-control study of multiple myeloma nested in the American Cancer Society prospective study — P. Boffetta, S.D. Stellman, et al. (1989)
• Exposure to chrysotile mining dust and digestive cancer mortality in a Chinese miner/miller cohort — S. Lin, X. Wang, et al. (2014)

Browse more research in American Journal of Industrial Medicine, or return to medical research.