Recorded presentation

Ilir Agalliu, MD, ScD¹, Ellen A. Eisen, ScD², David Kriebel, ScD², Margaret M. Quinn, ScD, CIH², and David H. Wegman, MD, MSc³. (1) Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N., M4-A402, P.O. Box 19024, Seattle, WA 98109, 206-667-7134, iagalliu@fhcrc.org, (2) Department of Work Environment, University of Massachusetts Lowell, 1University Avenue, Lowell, MA 01854, (3) Dean, School of Health and Environment, University of Massachusetts Lowell, 3 Solomont Way, Suite 1, Lowell, MA 01854-5121

To examine whether exposure to metalworking fluids (MWF) is associated with prostate cancer, we conducted a nested case-control study of 872 incident cases in a cohort of autoworkers. Our objectives were to examine exposure-response curves for MWF and prostate cancer by using semi-parametric modeling and explore time windows of exposure based on latency. Cases were identified through Michigan cancer registry from 1985 till 2000. Controls were selected using incidence-density sampling, 5:1 ratio. Using cumulative exposure (mg/m³-years) as the dose, we examined different lags and then consecutive exposure windows, for example: ³25 and <25 years before risk age. We used penalized splines to model risk as a smooth function of exposure, and controlled for race and calendar time of diagnosis. On average, cases were 70 years old when diagnosed, and 27% were black. Risk of prostate cancer was increased with exposure to soluble and straight MWF ³25 years before risk age, but not with exposure <25 years. The relationship with soluble was piecewise linear, with a small increase in risk at lower exposures followed by a steeper rise. By contrast, the relationship with straight MWF was linear with a relative risk of 1.12 per 10 mg/m³-years of exposure. Results provide evidence that exposure to MWF is associated with prostate cancer among autoworkers. They also support a latency period at least 25 years for prostate cancer development. This study also contributes to the literature of non-parametric modeling applied to occupational studies.

Learning Objectives:

• Describe approaches used to characterize exposure to metal working fluids.
• Explain the advantages of smoothing methods in modeling occupational data.
• Discuss the risk of prostate cancer associated with each type of metalworking fluid.

Keywords: Epidemiology, Occupational Health

Presenting author's disclosure statement:
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.

Recorded presentation