Timing of Aspirin Use in Colorectal Cancer Chemoprevention: A Prospective Cohort Study.
Yin ZhangAndrew T ChanJeffrey A MeyerhardtEdward L GiovannucciPublished in: Journal of the National Cancer Institute (2022)
A suggestive benefit necessitates at least 6-10 years and most clearly after approximately 10 years since initiation of aspirin. Remote use and use within the previous 10 years both contribute independently to decrease risk, though a lower dose may be required for a benefit with longer term use.