Try COX-2s to prevent colon cancer.(GUEST COMMENTARY)

Cyclooxygenase-2 inhibitors are appropriate as a supplemental strategy in the prevention of colorectal cancer in patients at highest risk for the disease.

The current standard for preventing colon cancer, colonoscopy and polypectomy, virtually eliminates the chances of polyps progressing to cancer. Colonoscopy is not perfect, however. About 5% of polyps are missed. As the scope moves through the colon, there are blind spots. In 1 out of 20 colonoscopies, a polyp will be left behind. That's typically not a major clinical problem; not all polyps progress to cancer.

Not all patients who have polyps are at the same risk of developing colon cancer. Clearly, there are some patients who are going to have a greater propensity to develop cancerous polyps. These include patients who have a history of adenomatous polyps which are greater than 1 cm in diameter, patients with numerous polyps, or patients with polyps that show a villous type of architecture on histology. The villous-type polyps are more likely to be aggressive in nature and to proceed to colon cancer.

High-risk patients typically undergo colonoscopy every 3 years, but polyps may grow at a rate in which the 3-year interval for surveillance may not be adequate. These high-risk patients--and I think "high risk" is the operative phrase here--should get adjunctive therapy in addition to colonoscopy to reduce the risk of progression from polyps to colon cancer. Options for adjunctive therapy include nonsteroidal anti-inflammatory drugs such as aspirin or a cyclooxygenase-2 (COX-2) inhibitor.

Three studies of COX-2 inhibitors have shown that administration of a COX-2 inhibitor is associated with a reduction in polyps in high-risk patients. Two prospective, randomized, placebo-controlled trials published in 2005 showed that COX-2 inhibitor preventive therapy with celecoxib or rofecoxib reduced the number of polyps in patients at high risk for colon cancer (N. Engl.J. Med. 2005;352:1071-80 and N. Engl.J. Med. 2005;352:1092-1102). A third study that has not yet been published--the ...