Nonsteroidal antiinflammatory drugs (
NSAIDs) use, particularly
aspirin, may lower the risk of several
cancers, including bladder.
NSAIDs may reduce development of
bladder tumors by decreasing
inflammation, inhibiting cycloxygenase-2, inhibiting proliferation and inducing apoptosis of
cancer cells. However,
acetaminophen, a major metabolite of
phenacetin, may be positively associated with
bladder cancer risk. Results from case-control studies on
NSAIDs and
acetaminophen use and
bladder cancer risk are inconsistent. We investigated the association between
NSAID and
acetaminophen use and
bladder cancer risk in a large cohort of US males. Among 49,448 men in the Health Professionals Follow-Up Study, 607
bladder cancer cases were confirmed during 18 years of follow-up. Relative risks (RR) and 95% confidence intervals (CI) were calculated by Cox proportional hazards models. Multivariate RR were adjusted for age, current smoking status, pack years, geographic region and fluid intake. No significant associations were observed for regular
aspirin (> or =2
tablets per week), (RR = 0.99, 95% CI 0.83-1.18),
ibuprofen (RR = 1.11, 95% CI 0.81-1.54),
acetaminophen (RR = 0.96, 95% CI 0.67-1.39) or total
NSAID use (not including
acetaminophen; RR = 1.01, 95% CI 0.85-1.20) and
bladder cancer risk compared with nonuse. Consistent use (over 6 years) of
aspirin,
ibuprofen,
acetaminophen and total
NSAIDs, compared to nonuse, was not associated with
bladder cancer risk. No association was observed between
aspirin frequency and dose and
bladder cancer risk. We observed no effect-modification by smoking, age or fluid intake. Our results suggest that regular
NSAID or
acetaminophen use has no substantial impact on
bladder cancer risk among men.