I read with interest the article by Dr Werner and colleagues (“Which healthy adults should take aspirin?,” J Fam Pract 2004; 53:146–150). However, the authors did not mention the role of aspirin in prevention of colorectal cancer. In randomized trials low-dose aspirin therapy demonstrated risk reduction on colorectal adenomas (precursors of colorectal cancer). Even 81 mg/d revealed a protective effect.1 Such a small dose might minimize adverse effects as aspirin-related gastrointestinal bleeding. Therefore, persons at higher risk for colorectal neoplasia might also benefit from low-dose aspirin therapy.
Martin Ritt, MD,
Medical University Innsbruck, Austria
Drs Kelsberg and Werner respond:
Thank you for your letter regarding the role of aspirin in the prevention of colorectal cancer. In our literature search for the question: “Which healthy adults should take aspirin?,” we also encountered the article you cited. However, that study and others like it looked at aspirin for secondary prevention in patients with prior colon cancer or adenomas. They showed a 5% to 10% absolute decrease in the number of recurrent adenomas with aspirin.
However, it is not yet clear if this would translate into a reduction in colon cancer morbidity or mortality. We found no literature in support of aspirin use for primary prevention of colon cancer. Since we interpreted the question to mean: “Which adults should take aspirin for primary prevention?” we elected to focus on cardiovascular protection where the evidence for primary prevention is already robust. We will be interested to see if future studies expand the preventive role of aspirin to include colorectal cancer.
Gary Kelsberg, MD, Matt Werner, MD,
Valley Family Medicine, Renton, Wash