Old Breast Cancer Drug Still No. 1
But while the oncology group is passing on aromatase inhibitors for now, they are not closing the door on the drugs. Winer says that there are ongoing studies that "may present sufficient data within two or three years, so we are going to revisit this issue every year."
Moreover, he says that even with the new recommendations, there are some women who should be getting aromatase inhibitors instead of tamoxifen. "Women with a history of blood clotting disorders would be good candidates for aromatase inhibitors because tamoxifen can increase the risk for clot formation," he says.
In addition, some women who have never had breast cancer before but are at a high risk for breast cancer take tamoxifen as a way to lower their risk. "So it is pretty much a no-brainer that if one of these women develops breast cancer, she is obviously not a good candidate for more tamoxifen, so an aromatase inhibitor would be a better choice."
And not all of the oncologists at the meeting agree with the new guidelines. Paul Goss, MD, director of the Breast Cancer Prevention Program at Princess Margaret Hospital in Toronto and professor of medicine at the University of Toronto, Ontario, said he believes "these recommendations are too cautious." He points out that for more than 15 years there has been ample evidence that limiting estrogen production is an effective way to prevent breast cancer.
For doctors and patients who decide to follow the tamoxifen recommendation, Kathy Albain, MD, professor of medicine at Loyola University Cardinal Bernardin Cancer Center in Chicago, says that there is a right and wrong way to take tamoxifen. She says that results of a study of 1,477 postmenopausal women with breast cancer suggest that taking tamoxifen at the same time as chemotherapy "reduces tamoxifen's benefit by half."
To get the maximum benefit, tamoxifen should be initiated after chemotherapy is completed, usually about six months after surgery.