Reduction in the risk of breast cancer with the use of selective COX-2 inhibitors

 

We observed a 71% reduction in the risk of breast cancer with the use of selective COX-2 inhibitors, such as Celebrex and Vioxx, for two years or more.   Significant reductions 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.  Overexpression of COX-2 has been linked to many components of carcinogenesis including the local biosynthesis of estrogen by activation of the gene for aromatase.  We did not observe effects of acetaminophen or low dose (81 mg) aspirin, neither of which has significant COX-2 activity. 

 

    Our results 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, additional clinical studies focussed on dosage and duration are needed in order to clarify how they might be used with the greatest beneficience. 

 

 
Randall E. Harris
Center of Molecular Epidemiology, College of Medicine and Public Health, The Ohio State University Medical Center, Columbus, Ohio