ASCO: aromatase inhibitor can replace tamoxifen.(News)

Postmenopausal women with hormone receptor-positive breast cancer can take an aromatase inhibitor instead of tamoxifen as adjuvant therapy, the American Society of Clinical Oncology concluded in a technology-assessment statement.

Aromatase inhibitor adjuvant therapy may be associated with a higher rate of osteoporosis, but initial data indicate equal or better effectiveness than tamoxifen therapy in preventing cancer recurrence--particularly in women on tamoxifen therapy for 2-3 years and then switched for the remainder of 5 years, the statement said.

The statement reflects what is already common clinical practice, commented Richard Elledge, M.D., medical director of the breast care center at Baylor College of Medicine, Houston.

But there is still no real information to guide clinicians in selecting the patients who may be most appropriate for an aromatase inhibitor instead of tamoxifen, and there is need for even more long-term data, he added.

Longer-term data from two pivotal trials are expected to be announced in the next few months, said Dr. Elledge, a researcher who was not involved with the statement.

"This still remains an area undergoing rapid evolution," he said. "Right now, we just have this sea change."

Two nonsteroidal aromatase inhibitors, anastrozole and letrozole, are ...