Wood Dust Exposure and the Risk of Upper Aero-Digestive and Respiratory Cancers in Males

¹ Division of Cancer Prevention and Population Sciences, Roswell Park Cancer Institute, Buffalo, United States
² Dept of Biostatistics, School of Public Health, University of North Carolina at Chapel Hill, NC, United States
³ Department of Head & Neck/Plastic Surgery, Roswell Park Cancer Institute, Buffalo, NY, United States
⁴ Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY, United States

^* To whom correspondence should be addressed. E-mail: mary.reid{at}roswellpark.org.

Accepted 14 December 2007

	Abstract

Background: Wood dust (WD) has been designated as a human carcinogen that can cause sino-nasal cancers. However, evidence on its association with other upper aero digestive tract and respiratory (UADR) cancers is inconsistent.

Objective: To examine the relationship between WD exposure and the risk of different histological sub-types of UADR cancers.

Methods: In a hospital based case-control study conducted at Roswell Park Cancer Institute, Buffalo, NY, USA; we examined the effect of self reported WD exposure on 1522 male UADR cancer cases (241 oral and oropharyngeal, 90 nasal cavity, nasopharyngeal and hypopharyngeal, 124 laryngeal, 809 lung and tracheal and 258 cancers of esophagus and gastric cardia) and 1522 male controls; frequency matched on age and smoking history. Odds ratios (OR) were calculated after adjusting for relevant risk factors including tobacco smoking.

Results: The results show that regular WD exposure was associated with a statistically significant increased risk of 32% for all UADR cancers [Adjusted OR =1.32 (95%CI = 1.01–1.77); p-trend =0.05] and 69% for lung cancer alone [Adjusted OR =1.69 (1.20–2.36); p-trend =0.007]. WD was associated with 82-93% increased risk of squamous cell, small cell and adenocarcinoma of lung and more than twice the risk of developing squamous cell carcinoma of nasal cavity, nasopharynx and hypopharynx; with a significant dose-response relationship. Oral and oropharyngeal cancers showed a non-significant increase in risk. Significant increase in risk of laryngeal and lung cancers was noted for subjects who were regularly exposed to WD for more than 20 years. Cancers of esophagus and gastric cardia did not show any risk associated with WD. WD was associated with a significantly greater risk of UADR cancers among people who have ever smoked than never smokers.

Conclusion: WD exposure is a potential risk factor for UADR cancers, especially for cancers of nasal cavity, nasopharynx, larynx and lung.

Keywords: Lung cancers, Men, Occupational exposures, Upper aero-digestive cancers, Wood dust