Nested case-control study of occupational chemical exposures and prostate cancer in aerospace and radiation workers.
BACKGROUND
To date, little is known about the potential contributions of occupational exposure to chemicals to the etiology of prostate cancer. Previous studies examining associations suffered from limitations including the reliance on mortality data and inadequate exposure assessment.


METHODS
We conducted a nested case-control study of 362 cases and 1,805 matched controls to examine the association between occupational chemical exposures and prostate cancer incidence. Workers were employed between 1950 and 1992 at a nuclear energy and rocket engine-testing facility in Southern California. We obtained cancer-incidence data from the California Cancer Registry and seven other state cancer registries. Data from company records were used to construct a job exposure matrix (JEM) for occupational exposures to hydrazine, trichloroethylene (TCE), polycyclic aromatic hydrocarbons (PAHs), benzene and mineral oil. Associations between chemical exposures and prostate cancer incidence were assessed in conditional logistic regression models.


RESULTS
With adjustment for occupational confounders, including socioeconomic status, occupational physical activity, and exposure to the other chemicals evaluated, the odds ratio for low/moderate TCE exposure was 1.3; 95%CI = 0.8 to 2.1, and for high TCE exposure was 2.1; 95%CI = 1.2 to 3.9. Furthermore, we noted a positive trend between increasing levels of TCE exposure and prostate cancer (P-value for trend = 0.02).


CONCLUSIONS
Our results suggest that high levels of TCE exposure are associated with prostate cancer among workers in our study population.
Krishnadasan
Anusha
A
Department of Epidemiology, School of Public Health, University of California, Los Angeles, CA, USA. akrishna@ucla.edu
Kennedy
Nola
N
Zhao
Yingxu
Y
Morgenstern
Hal
H
Ritz
Beate
B
D000328:Adult; D000368:Aged; D001359:Aviation; D002140:California / Q000453:epidemiology; D016022:Case-Control Studies; D006801:Humans; D006834:Hydrazines / Q000633:toxicity*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D016273:Occupational Exposure / Q000009:adverse effects*; D011084:Polycyclic Aromatic Hydrocarbons / Q000633:toxicity*; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000209:etiology; D011827:Radiation; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D014241:Trichloroethylene / Q000633:toxicity*; D014481:United States / Q000453:epidemiology
D006834:Hydrazines; D011084:Polycyclic Aromatic Hydrocarbons; C029424:hydrazine; D014241:Trichloroethylene