ORIGINAL CONTRIBUTION JAMA-EXPRESS Low-Dose Aspirin in the Primary Prevention of Cancer The Women’s Health Study: A Randomized Controlled Trial

A GROWING BODY OF LITERA-ture supports a protectiveeffect of aspirin and othernonsteroidal anti-inflamma-tory drugs (NSAIDs) on the develop-ment of cancer. In experimental ani-mal models, NSAIDs have been shown to suppress tumor growth.1,2 Observa-tional epidemiological investigations suggest a strong inverse association, with risk reductions as high as 20 % to 50 % for various cancer sites,3 includ-ing but not limited to colorectal can-cer,4,5 breast cancer,6 and gastric can-cer.3 In addition, polyp prevention trials have consistently demonstrated a beneficial effect of aspirin and other NSAIDs on recurrence of colorectal adenomas.5 Aspirin is thought to influence can-cer risk primarily through its effect on cyclooxygenase (COX) activity. Aspi-rin, as well as other NSAIDs, inhibits the COX enzymes, which convert ara-chidonic acid into prostaglandins.7 The proposedmechanism for aspirin’s effect See also pp 56 and 105. AuthorAffiliations:DivisionsofPreventiveMedicine (Dr