Evaluation of non-aspirin NSAID use alone was further complicated by the
general lower frequency of non-aspirin NSAID use in this population: merely
13.4% used non-aspirin-only. Because aspirin is the most commonly used drug
for cardiovascular disease prevention, this study might lack the power to detect
diminished risks associated with non-aspirin NSAID use. However, we did
improve the power by combining cancers with like inflammation-related causes.
Our study had several strengths. The NIH-AARP Diet and Health Study is a
large cohort with detailed information on NSAID use, which allowed us to
evaluate less common cancers. The detailed collection of epidemiologic
information enabled us to examine the effect of multiple confounders, such as
diabetes, smoking, obesity, and cardiovascular diseases. However, certain
limitations have to be noted. We did not have information on the indication for
NSAID use. However, our results were similar when restricted to individuals
without a history of cardiovascular disease and non-diabetics, suggesting that use
NSAIDs and Inflammation-Associated Cancers
PLOS ONE of NSAIDs for cardiovascular disease does not modify the results. Finally,
cumulative exposure or dosage could not be evaluated.
In summary, our results indicate that NSAID use might reduce the risk of
several cancers. The null results for some cancers might indicate that NSAIDs
need to be used for a prolonged duration to exert a measurable effect. Taken
together, these results warrant further studies on the dosage and duration of
NSAID use for chemoprevention of inflammation-related cancer. Such studies
will pave the way to a well-designed chemoprevention clinical trial to establish the
lowest safest dose and duration required for chemoprevention of different cancer
subsites.