Celebrex for Preventing Colon Cancer? No!

The cardiovascular problems with Celebrex®, which spread to include all the COX-2 anti-inflammatory drugs such as Vioxx®, were discovered in a study of its possible value in preventing colon cancer. Most of the attention in that study was focused on the reported side effects that led to the withdrawal of Vioxx and black-box warnings for Celebrex. But there’s still interest in whether anti-inflammatory drugs have a protective effect in reducing the occurrence of pre-malignant colon polyps, or adenomas. The results of a second study have just been reported in the New England Journal of Medicine.

There were over 1,500 participants treated in 32 countries with 400 mg Celebrex once daily, or a placebo. At the end of the study, 34% of the Celebrex subjects had developed colon adenomas (removed on colonoscopy), compared with 49% given the placebo. And there was a 50% reduction in larger, potentially more dangerous, adenomas. There was no increase, however, in the cardiovascular risk rate.

Does this mean that COX-2 inhibitors should be used routinely for colon cancer prevention in high-risk people? Not really – the risk of cardiovascular side effects has been seen in too many instances, not to be taken seriously. But the investigators point out that in their study, where no cardiac problems were seen, Celebrex was given once daily, whereas in the first study that led to all the trouble it was given at 200 or 400 mg twice daily.

Low-dose aspirin has been shown to reduce adenoma formation in people at high risk, and it can also decrease cardiovascular risk; on the other hand, it can increase the risk of gastric bleeding and stroke. As we’ve said before, there are no therapeutic roses without thorns.