Study finds less breast cancer in COX-2 drug users

Last Updated: 2006-04-04 14:00:30 -0400 (Reuters Health)

WASHINGTON (Reuters) - Patients who took prescription pain relievers known as COX-2 inhibitors were less likely to develop breast cancer than others who did not have a history of taking the drugs, a study released on Tuesday said.

Researchers said they would not yet suggest use of COX-2 drugs for preventing breast cancer, in part because they have been linked to a higher risk of cardiovascular problems.

The only COX-2 inhibitor now being sold in the United States is Pfizer Inc.'s Celebrex. Merck & Co. Inc.'s Vioxx was pulled from the market in 2004 after it was linked to heart attacks and strokes, while Pfizer's Bextra was withdrawn in 2005 after reports of a life-threatening skin reaction.

"We're concerned about potential side effects of these agents, and before making recommendations for their use, further studies are needed to determine if low dosages that cause no harm have consistent preventive effects against cancer," said Dr. Randall Harris, director of the Center of Molecular Epidemiology at the Ohio State University Medical Center in Columbus, Ohio.

Harris and his colleagues compared the habits of 323 breast cancer cases to 649 people without the disease. Use of a COX-2 drug reduced breast cancer risk by 71 percent, the researchers reported at a meeting of the American Association for Cancer Research in Washington.

Evidence is growing that blocking the COX-2 enzyme, a key component of inflammation, might help fight some cancers. On Monday, two large studies showed high doses of Celebrex taken daily for three years reduced the formation of pre-cancerous growths in the colon.