Nested case-control study of occupational physical activity and prostate cancer among workers using a job exposure matrix.
OBJECTIVE
We conducted a nested case-control study of 362 cases diagnosed between 1 January 1988 and 31 December 1999, and 1,805 matched controls to examine the association between occupational physical activity and prostate-cancer incidence among workers at a nuclear and rocket engine-testing facility in Southern California.


METHODS
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 physical activity during employment. Conditional logistic regression was used to estimate associations.


RESULTS
With adjustment for occupational confounders, including socioeconomic status and trichloroethylene (TCE) exposure, high activity levels at work were inversely associated with prostate-cancer incidence among aerospace workers (odds ratio [OR] = 0.55; 95% CI = 0.32-0.95), but not among radiation workers (OR = 0.95; 95% CI = 0.43-2.1).


CONCLUSIONS
Our results suggest that adult men who are more continually active at work may have a decreased risk of prostate cancer.
Department of Epidemiology, School of Public Health, University of California-Los Angeles, CA, USA. akrishna@ucla.edu
Anusha
A
Krishnadasan
Nola
N
Kennedy
Yingxu
Y
Zhao
Hal
H
Morgenstern
Beate
B
Ritz
D001554:Benzene / Q000009:adverse effects; D016022:Case-Control Studies; D003625:Data Collection; D006801:Humans; D006834:Hydrazines / Q000009:adverse effects; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D016273:Occupational Exposure; D009790:Occupations; D011084:Polycyclic Aromatic Hydrocarbons / Q000009:adverse effects; D011471:Prostatic Neoplasms / Q000139:chemically induced / Q000453:epidemiology*; D014241:Trichloroethylene / Q000009:adverse effects
D006834:Hydrazines; D011084:Polycyclic Aromatic Hydrocarbons; C029424:hydrazine; D014241:Trichloroethylene; D001554:Benzene