The General Motors/United Auto Workers (GM/UAW) cohort includes 46,000 auto workers exposed to metalworking fluids (MWFs) at three Michigan plants. To date, a third of the cohort is deceased. A recent extension of follow-up through 1994 has identified sufficient cases to conduct separate nested case-control studies of three rare gastrointestinal cancers: liver, gallbladder and pancreas. All cases were confirmed by the Michigan cancer registries and matched to 10 controls per case. In the period that the registries were active, 95% of the death certificates listing gallbladder cancer as the underlying cause of death were validated by the registries. Validation for the other two cancers was less than 80%. Deaths occurring out of state or prior to the start-up of the registries could not be confirmed. Relying on estimates of lifetime exposure to MWFs and selected components, conditional logistic regression models were fit to estimate exposure-response relationships. No associations were found for liver cancer, despite elevated Standardized Mortality Ratios. When exposures were limited to those occurring 10 years prior to case's death, an excess risk of gallbladder cancer was associated with aluminum exposure, Odds Ratio (OR)=6.1, 95% Confidence Interval (CI): 1.5-25. The risk persisted when limited to confirmed cases, but the confidence interval widened. An elevated risk for pancreatic cancer associated with ethanolamines containing nitrosamines (OR=2.5, 95%CI: 0.8-7.4) was found in confirmed cases. Risk was not observed with ethanolmines that were free of nitrosamines. Results suggest aluminum and nitrosamines may be acting as cancer promotors in MWFs in the work environment.
Learning Objectives: Describe etiology and occupational risk factors for liver, gallbladder and pancreatic cancer. Describe models of exposure-response relationships for metalworking fluids and its components and the risk of liver, gallbladder and pancreatic cancer. Discuss conclusions, and the implications for occupational health in the work environment
Keywords: Cancer, Occupational Exposure
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.