The WHS trial was led by BWH researchers Nancy Cook, Sc.D., and Julie Buring, Sc.D. Its results are published in the July 6, 2005 Journal of the American Medical Association. It monitored 39,876 healthy females 45 years of age and older for cancer and cardiovascular events including heart attack, stroke, and death from cardiovascular causes. Results demonstrated aspirin therapy reduced stroke risk by 17 percent but did not decrease heart attacks or cardiovascular deaths among all women. In the women 65 years and older, aspirin reduced the risks of cardiovascular disease, ischemic stroke, and heart attack.
Primary endpoints in the aspirin study were any invasive cancer, excluding non-melanoma skin cancer, with breast, colorectal and lung cancer as secondary endpoints. A total of 2,865 cases of invasive cancer were confirmed. Of these, 1,230 were breast cancer, 269 were colorectal cancer, and 205 were lung cancer, with no significant difference between the aspirin and placebo groups except for a trend towards reduced lung cancer in the active aspirin group.
The WHS found that vitamin E had no overall benefits on cardiovascular disease or cancer. However, it did reduce cardiovascular deaths among all women, as well as overall cardiovascular disease in the subgroup of women age 65 years and older.