Celebrex may help fight colon cancer
WASHINGTON – Celebrex, the once-celebrated painkiller now beset by heart attack concerns, may reduce the risk of growths that can lead to colon cancer, researchers reported Monday.
In two separate studies, those who took the drug daily were significantly less likely than those who took a placebo to have precancerous growths three years later. The effect was even more pronounced among participants at the highest risk.
“It really exceeded our expectations,” said Dr. Monica Bertagnolli, of Brigham and Women’s Hospital in Boston.
The results may leave people worried about colon cancer with a dilemma: Is a lower risk of cancer worth a greater risk of cardiovascular disease?
“I think we’re in a quandary,” said Dr. Ernest Hawk, of the National Cancer Institute, a sponsor of one trial. For now, doctors say, it’s too early to make any recommendations about the drug.
Celebrex falls in the class of drugs known as cox-2 inhibitors. The anti-inflammatory drugs were heralded at their debut, boasting pain relief that was easier on the stomach.
In 2004, however, cox-2 inhibitors fell from grace after researchers raised questions about cardiovascular safety. Two other cox-2 inhibitors, Vioxx and Bextra, have already been withdrawn from the market.
Scientists have been investigating the anti-cancer potential of cox-2 inhibitors for years. Laboratory studies have found that both precancerous and malignant cells usually overproduce cox-2, and have suggested that shutting down the enzyme may interrupt cells on the road to cancer. Early studies hinted that Celebrex might lower the occurrence of precancerous growths in people with an extremely strong family history. But until Monday, doctors did not know whether Celebrex might live up to its anticancer potential in people with a more typical colon cancer risk.
During the annual meeting of the American Association for Cancer Research in Washington, scientists described two studies, funded in part by drug maker Pfizer.
In research presented by Bertagnolli and her colleagues, about 2,000 patients who had a known risk for colon polyps were randomly assigned to receive two different doses of Celebrex or a placebo.
After three years, 61 percent who took a placebo had precancerous growths. Among those who received 200 milligrams of Celebrex twice daily, 42 percent had the growths. It was 37 percent among those who took 400 milligrams twice daily.
In a second trial, more than 1,500 patients received 400 milligrams of Celebrex daily or a placebo for three years. Overall, Celebrex reduced the risk of precancerous growths by about a third.