Daily aspirin usage is associated with a lower overall cancer mortality, but this association may be smaller than what has been reported in the literature and conveyed in the media.
Eric Jacobs, PhD, and colleagues examined the association between reported daily aspirin use and overall cancer mortality among 100,139 men and women with no history of cancer who participated in the Cancer Prevention Study II Nutrition Cohort. The researchers sent follow-up questionnaires to determine if the study participants took aspirin and found that among 5,138 participants who died from cancer, daily aspirin usage was linked with a slightly lower cancer mortality. However, the estimated reduced risk of 16% observed in this study was lower than the 37% reduction observed in prior randomized trials of aspirin use as a preventive measure for vascular events. These studies also found a 15% reduction in cancer mortality during the ten-year follow-up time periods. Consequently, it appears that aspirin does indeed reduce cancer mortality; however, risk reduction is likely lower than previously believed.
The researchers noted that a major limitation of the study was that it was an observational study and not a randomized trial, so confounding variables could have impacted their findings. Also, prior to recommending prophylactic aspirin use, the risks and benefits of aspirin use for each individual needs to be considered. For some, the potential risks (e.g. bleeding, etc.) will outweigh the potential benefit.
Jacobs EJ, Newton CC, Gapstur SM, Thum MJ. Daily aspirin use and cancer mortality in a large US cohort. J Natl Cancer Inst. 2012; 104(16): 1208-1217.