The regular use of certain COX-2 inhibitors and other NSAIDs apparently leads to a significant reduction in breast cancer risk, researchers report in the journal BMC Cancer.

Dr. Randall Harris and colleagues at the Ohio State College of Medicine and Public Health in Columbus studied 323 breast cancer patients and 649 cancer-free controls.

“We observed a 71 percent reduction in the risk of breast cancer with the use of selective COX-2 inhibitors, such as Celebrex and Vioxx, for 2 years or more,” said Harris.

“Significant reductions,” he added, “were also observed for ibuprofen and regular - 325 mg - aspirin, but of lesser magnitude.”

“We suggest that these effects were produced by inhibition of COX-2, the rate limiting enzyme of the prostaglandin cascade,” Harris said. In support of this, no significant change in breast cancer risk was seen with acetaminophen, which has negligible COX-2 activity, or with low-dose (81 mg) aspirin.

“Our results,” said Harris, “underscore the major role of COX-2 overexpression in mammary carcinogenesis and the potential for chemoprevention and quite possibly therapy with selective COX-2 blocking agents.”

“Since COX-2 inhibitors may also reduce the risk of other cancers and influence the cardiovascular system as well,” he concluded, “additional clinical studies focused on dosage and duration are needed in order to clarify how they might be used with the greatest beneficence.”

SOURCE: BMC Cancer 2006.