Tamoxifen, an antiestrogenagent that has been used for >20years to treat breast cancer, doesnot increase a woman's risk forstroke. Earlier studies had indicatedthat the drug could increase awoman's risk. Reporting in theJournal of the National CancerInstitute (October 20, 2004), studycoauthor Ann Geiger, PhD, saidthat the previous studies did notindependently confirm the strokediagnosis, and they did not controlthe data for the participants'otherrisk factors for stroke.
Therefore, the researchers enrolled>11,000 women who hadbeen diagnosed with breast cancerbetween 1980 and 2000 and evaluatedthe risk of stroke fromtamoxifen treatment. The datashowed that 422 women had possiblestrokes. Of these 422women, 49 were excluded becausethe stroke happened prior tothe breast cancer diagnosis.Another 194 were not eligibleeither because their stroke couldnot be confirmed or because theresearchers could not gatherenough tamoxifen information.
The remaining 179 women withconfirmed strokes after their breastcancer diagnosis were comparedwith 431 control patients who wereage-matched and had similarbreast cancers. The researchersfound no connection betweentamoxifen and stroke.