Researchers from the Massachusetts General Hospital (MGH) Cancer Center and Arcturus Bioscience, Inc., describe their findings in a report to be published in the June issue of Cancer Cell. The paper is being released online today (www.cancercell.org) because related material is being presented at the June 5-8 American Society for Clinical Oncology meeting. The study was supported by grants from the Avon Foundation, the U.S. Department of Defense, and the National Cancer Institute.
Tamoxifen, which blocks the interaction between the hormone estrogen and its receptor protein, is used to treat breast cancers that express the estrogen receptor. However, only two thirds of these patients have a prolonged response to the drug. "Until now, there has been no way to predict which estrogen-receptor-positive patients will not respond to tamoxifen treatment," says Dennis Sgroi, MD, director of Breast Pathology at MGH who led the hospital's research team. "Identifying those for whom tamoxifen is likely to fail could allow physicians to choose other drugs, for instance the aromatase inhibitors that more completely block estrogen's action." Sgroi is an associate professor of Pathology at Harvard Medical School.
The hormone estrogen can stimulate both the normal growth of breast tissue and the uncontrolled growth of breast cancer. Cells from most breast tumors contain estrogen receptor molecules, indicating that the tumor's growth is likely to be sensitive to the hormone's action. Estrogen-blocking drugs have been used in recent years to prevent hormone-sensitive breast tumors from recurring after surger
Contact: Sue McGreevey
Massachusetts General Hospital