A cohort study of farming and risk of prostate cancer in Iowa.
Although farming has been linked to prostate cancer mortality, few investigations have addressed its association with prostate cancer incidence. We followed a population-based cohort of 1,177 cancer-free men for up to 9 years and identified 81 incident prostate cancers. Men whose usual occupation was farmer were at an increased risk of prostate cancer after adjustment for age, smoking, alcohol, and dietary factors (RR = 1.7; 95% CI = 1.0-2.7). Exclusion of well-differentiated, localized tumors slightly strengthened the association (RR = 2.0; 95% CI = 1.1-3.6). Risk was confined to older (age 70+ years) farmers (RR = 2.2; 95% CI = 1.1-4.3); we found no evidence of an effect among younger farmers (RR = 1.0; 95% CI = 0.4-2.1).
Parker
A S
AS
Department of Preventive Medicine and Environmental Health, The University of Iowa, College of Medicine, Iowa City, USA.
Cerhan
J R
JR
Putnam
S D
SD
Cantor
K P
KP
Lynch
C F
CF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000383:Agriculture; D000428:Alcohol Drinking; D016022:Case-Control Studies; D006801:Humans; D015994:Incidence; D007484:Iowa / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016272:Occupational Health; D011471:Prostatic Neoplasms / Q000453:epidemiology*; D012307:Risk Factors; D012907:Smoking