Medical researchers say a new study shows women who regularly take aspirin may lower their risk of developing the most common type of breast cancer.

Cancer researchers say a study of nearly 3000 women in New York found those who regularly took aspirin had a lower incidence of breast cancer than those who did not take aspirin.

Dr. Alfred Neugut is professor of medicine at Columbia University and one of the study's researchers. ?Taking an aspirin a day, presumably reduces your risk of getting breast cancer by roughly 25 percent and that the specific type of breast cancer that's prevented is what one might characterize as estrogen-dependent breast cancer,? he noted.

Dr. Neugut said that aspirin appears to suppress the production of the hormone estrogen in the breast. Estrogen is partly responsible for causing the type of breast cancer that accounts for about 70 percent of all breast cancer cases.

About one in eight American women will develop breast cancer.

Doctors say the study's findings do not mean that women should begin regularly taking aspirin, because more research is needed on the potential side effects of the drug. However, women who currently take aspirin for other medical conditions, may also be lowering their risk of breast cancer.

Researcher Andrew Dannenberg says the study is also significant because it marks an important milestone in understanding and preventing cancer.

?In cardiology we know that using drugs such as anti-hypertensive agents protects against coronary artery disease,? he said. ?Oncology is probably 15 to 20 years behind, but this study represents a critical point because it illustrates preventing cancer as opposed to simply waiting to develop cancer.?

The study's findings are published in the May 26 issue of The Journal of the American Medical Association.