Letrozole, a drug that derails the body's production of estrogen, reduces breast cancer recurrences in women who have exhausted the usefulness of the anticancer drug tamoxifen, a new drug trial has revealed.
Tamoxifen stops breast cancers in many women by interfering with estrogen's proliferative effect on tumor cells. But taking tamoxifen for more than 5 years provides no additional benefit, compared with going off the drug after that period.
Researchers identified 5,157 post-menopausal women who had taken tamoxifen for about 5 years and randomly assigned them to take either an inert pill or letrozole, which wipes out nearly all estrogen in the body.
The scientists stopped the study when it became clear that the group receiving letrozole had roughly three-fifths as many breast cancer recurrences as did women getting the placebo, says study coauthor Paul E. Goss, a medical oncologist at Princess Margaret Hospital in Toronto. Researchers then offered letrozole to a