A modest but significantly reduced risk for overall cancer, especially gastrointestinal tract tumors, was observed with long-term aspirin use among 88,084 women and 47,881 men who underwent follow-up in 2 large US prospective cohort studies and reported on aspirin use biennially. Researchers found:

• Compared with nonregular use, regular aspirin use was associated with a lower risk for overall cancer (RR=0.97), which was primarily owing to a lower incidence of gastrointestinal tract cancers (RR=0.85), especially colorectal cancers (RR=0.81).

• Regular aspirin use may prevent a substantial proportion of colorectal cancers and complement the benefits of screening.

• The benefit of aspirin on gastrointestinal tracts cancers appeared evident with the use of at least 0.5 to 1.5 standard aspirin tablets per week with the minimum duration of regular use associated with a lower risk being 6 years.

• Among individuals aged ≥50 years, regular aspirin use could prevent 33 colorectal cancers per 100,000 person-years.

Citation: Cao Y, Nishihara R, Wu K, et al. Population-wide impact of long-term use of aspirin and the risk for cancer. [Published online ahead of print March 3, 2016]. JAMA Oncol. doi:10.1001/jamaoncol.2015.6396.