“There was a 65 percent reduction in the risk of breast cancer — a pill that can do that to the commonest cancer that affects women globally and kills women globally; there’s no such pill that I know of for any kind of cancer,’’ Dr. Paul E. Goss, director of the breast cancer research program at Mass. General and lead author of the study, said in an interview before presenting the findings at the meeting of the American Society of Clinical Oncology in Chicago.
“We haven’t seen any serious toxicity that might stifle someone’s decision to try and take this drug,’’ said Goss, who has received honoraria from several pharmaceutical companies, including a one-time speaker’s fee from Pfizer.
The paper was also published online yesterday by the New England Journal of Medicine.
The seven-year study followed 4,560 women from the United States, Canada, Spain, and France who were postmenopausal and had at least one risk factor for breast cancer, which could include being over age 60 or having a breast biopsy result that showed they were at higher risk. Women were randomly assigned to one of two groups: one group received a placebo, and the other took exemestane, which is already approved to treat women after they are diagnosed with breast cancer.
After a median follow-up of three years, there were 11 invasive breast cancers among the women receiving exemestane compared with 32 in the placebo group, and there were also fewer precursor lesions found in women taking the drug.
There were some side effects: More women on exemestane than the placebo suffered hot flashes, fatigue, sweating, and insomnia. The rate of bone fractures, osteoporosis, and cardiovascular effects was the same in both groups.
The study was funded by the Canadian Cancer Society and Pfizer.
