A daily dose of aspirin may provide a protective effect against cancer; however, the results of a new study published in the Journal of the National Cancer Institute indicate that the protective effect may be weaker than previous studies have found.
Aspirin is commonly recommended for the prevention of cardiovascular disease and several recent studies have also found a link between daily aspirin and reduced cancer incidence and mortality. What’s more, aspirin appears to reduce the risk of hereditary colon cancer. Despite the positive results from these studies, researchers continue to study the effects of daily aspirin—especially after long-term use.
Researchers conducted a study to evaluate the magnitude of the effect of long-term daily aspirin use on cancer mortality. The study included over 100,000 men and women with no history of cancer who participated in the Cancer Prevention Study II Nutrition Cohort.
The results of the study indicated that daily aspirin use was associated with a slightly lower mortality rate than no aspirin, regardless of the duration of use. Overall, people who took daily aspirin had a 16 percent lower risk of dying from cancer compared with those who did not take aspirin. The protective effect was strongest for gastrointestinal cancer, such as colon cancer and stomach cancer.
The researchers concluded that daily aspirin use is associated with a modestly lower risk of dying from cancer, but this effect might be smaller than previously thought based on the data from earlier studies. The protective effects of aspirin will likely continue to be studied.
The current clinical guidelines for the use of aspirin in disease prevention consider only its cardiovascular benefits, weighed against the potential harm from aspirin-induced bleeding. Individuals who wish to use aspirin for cancer prevention are advised to discuss the risks and benefits with their physician.
 Jacobs EJ, Newton CC, Gapstur SM, Thun MJ. Daily aspirin use and cancer mortality in a large US cohort. Journal of the National Cancer Institute. Published early online August 10, 2012. doi: 10.1093/jnci/djs318
 Thun MJ, Jacobs EJ, Patrono C. The role of aspirin in cancer prevention. Nature Reviews Clinical Oncology. Published early online April 3, 2012. doi:10.1038/nrclinonc.2011.199
 Rothwell PM, Price JF, Fowkes FGR et al. Short-term effects of daily aspirin on cancer incidence, mortality, and non-vascular death: analysis of the time course of risks and benefits n 51 randomised controlled trials. Lancet. Early online publication March 21, 2012.
 Burn J, Gerdes A-M, Macrae F et al. Long-term effect of aspirin on cancer risk in carriers of hereditary colorectal cancer: an analysis from the CAPP2 randomised controlled trial. Lancet. Early online publication October 28, 2011.