A clinical trial reveals that the drug exemestane can shrink breast tumors and is well tolerated.

Exemestane is one of a new group of drugs called the aromatase inhibitors. They bind to an enzyme involved in estrogen production in the breast. Their role in breast cancer is, like the more well-known drug tamoxifen, to block the action of estrogen in tumors that are otherwise stimulated by it. But aromatase inhibitors act on a different part of the pathway.

In a trial conducted by researchers at the Catholic University Leuven in Belgium 122 patients with breast cancer were given either tamoxifen or exemestane. Side effects, such as fatigue, bone pain, and hot flashes were similar among both groups. Those treated with exemestane had greater shrinkage of their tumors than those who received tamoxifen.

It is too soon to say that exemestane is more effective than tamoxifen - this must wait for larger trials. But any new options in breast cancer are to be welcomed and it's also possible that exemestane could be used to prevent the disease.

Source

Annals of Oncology September 2003