To the Editor We read with interest the article by Cao et al1 that, in a large population cohort, demonstrated the benefit of regular use of low-dose aspirin in lowering the risk of gastrointestinal, and particularly colorectal, cancer. This important finding, which was suggested for the first time in 1988 by Kune et al,2 confirms the results of previous large observational studies and supports the recent recommendations of the US Preventive Service Task Force.3