Table 1 ASPIRED eligibility criteria

• Adenoma removed during qualifying endoscopy (as confirmed by pathology)

• Not currently taking aspirin (any dose) within the last 6 months

• Age 18–80 years

• Able to swallow pills

• Ability to understand and the willingness to sign a written Informed Consent Document

• ECOG performance status ≤2

• (Karnofsky Index score ≥60%)

• Any adenoma that was not completely removed during previous colonoscopy

• Known diagnosis of familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (HNPCC, Lynch syndrome)

• Diagnosis of inflammatory bowel disease, liver or kidney disease, or bleeding diathesis

• Any prior diagnosis of gastrointestinal cancer (including esophageal, small intestinal, colon, pancreatic), or any diagnosis of other cancers (with the exception of non-melanomatous neoplasia of skin) in which there has been any active treatment within the last 3 years

• Use of any nonaspirin, nonsteroidal anti-inflammatory drug (NSAID) at any dose at least 3 times/week during the 2 months prior to randomization

• History of aspirin intolerance, bleeding diathesis, peptic ulcer or gastrointestinal bleed, endoscopic complications, or contraindication to colonoscopy

• History of allergic reactions attributed to compounds of similar chemical or biologic composition to aspirin

• Taking any anticoagulant agent (e.g., warfarin) or antiplatelet agent (e.g., clopidogrel)

• Receiving any other investigational agents

• Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements

• Pregnant or breastfeeding