Aspirin/Folate Prevention of Large Bowel Polyps

This is a randomized controlled trial of aspirin and/or folate supplementation for the prevention of the recurrence of neoplastic polyps (adenomas) of the large bowel among subjects with a recent history of these tumors. The study is a randomized, double-blind, placebo-controlled trial with a 2 x 3 factorial design.

Inclusion criteria

• One neoplastic polyp removed within three months of study entry or within 16 months of study entry if over 1 cm in size or if subject has had a lifetime history of at least two polyps, with the entire large bowel seen by colonoscopy to be free of further polyps within 3 months of entry.
• An ability and willingness to follow the study protocol, as indicated by the subject's giving informed consent to participate.
• Good general health, with no severely debilitating diseases or active malignancy that might compromise the patient's ability to complete the study.
• Anticipated colonoscopic follow-up three years after the qualifying colonoscopy.
• Age between 21 and 80 years at the time of the intake colonoscopy.
• For women of childbearing potential, agreement to use effective birth control for the duration of the study.
• Intent not to take aspirin or aspirin-containing products, NSAIDs or folic acid for the length of the study unless required by a physician.
• Not randomized previously or currently in a chemoprevention trial, except for the: "Nutritional Prevention of Large Bowel Polyps" Study (Polyps Prevention Study I); and brief participation in the "VA Cooperative Study" with no continuing involvement.

Exclusion criteria

• Invasive carcinoma in any colonic polyp removed.
• Familial colonic polyposis syndromes.
• Ulcerative colitis or Crohn's disease.
• Malabsorption syndrome (e.g. pancreatic insufficiency).
• Large bowel resection for any reason.
• Diagnosed narcotic or alcohol dependence
• Contraindication to aspirin use, including:

• documented peptic ulcer disease in the past 20 years
• aspirin sensitivity
• bleeding diathesis, including hemorrhagic stroke
• Likelihood of NSAID use

• recurring arthritis or other musculo-skeletal problems
• frequent NSAID use in 5 years preceding
• history of stroke or TIAs
• history of angina or myocardial infarction
• desire to take aspirin for the prevention of cardiovascular disease
• Required or contraindicated folic acid use pernicious anemia or folic acid deficiency
• Pregnancy or lactation.