Tamoxifen Cuts Fracture Risk: Study

The new study adds to information about tamoxifen's effects, said Dr. Christy Russell, associate professor of medicine at the University of Southern California Keck School of Medicine, and chair of the American Cancer Society's Breast Cancer Advisory Group.

"We have known from large breast cancer trials comparing tamoxifen to aromatase inhibitors that the fracture rates were higher in [those who got] aromatase inhibitors than tamoxifen," she said. "But we had not known whether the fracture rate on tamoxifen was lower than in women not being given tamoxifen and given nothing. This study gives that information."

Russell said the study results may cause some doctors to rethink when they prescribe tamoxifen and aromatase inhibitors. Currently, some doctors use aromatase inhibitors alone for postmenopausal breast cancer patients, while others use tamoxifen then aromatase inhibitors. The new findings may lend weight to the value of giving tamoxifen first, she said.

Dr. Len Lichtenfeld, the American Cancer Society's deputy chief medical officer, said the take-home message from the new study was this: "If you switch from tamoxifen to aromatase inhibitors, or if you stop tamoxifen, you must be aware your osteoporosis risk may increase."

Women should then ask their doctor how best to protect their bone health, he said.

More information

To learn more about tamoxifen, visit the National Cancer Institute.

SOURCES: Andrew L. Cooke, M.D., head, radiation oncology, CancerCare Manitoba, Winnipeg, Manitoba, Canada; Christy Russell, M.D., associate professor, medicine, University of Southern California Keck School of Medicine, Los Angeles, and chair, American Cancer Society Breast Cancer Advisory Group; Len Lichtenfeld, M.D., deputy chief medical officer, American Cancer Society, Atlanta; Nov. 10, 2008,Journal of Clinical Oncology