Enzalutamide, a drug used to treat prostate cancer, may be effective against breast cancer. It targets androgen receptors, including testosterone, which has been implicated in prostate cancer. But a clinical trial at the University of Colorado has been studying how Enzalutamide might affect breast cancers. They presented their research at a poster session at the San Antonio Breast Cancer Symposium.
Some 75 percent of all breast cancers and about 20 percent of triple negative (TNBC) cancers are positive for the androgen receptor. That means a drug that targets prostate cancer might work against breast cancer.
This is especially significant for TNBC, a disease defined by what it lacks— receptors for the hormones estrogen, progesterone, and her2/neu. Because it lacks these receptors, it lacks a targeted drug, although chemotherapy, radiation, and surgery have been effective against the disease. Blocking the androgen receptor may stop the growth of some triple negative breast cancers, which might lead to targeted therapy.
A phase I clinical trial of Enzalutamide for triple-negative breast cancers is expected to become a Phase II trial. The trials are offered at CU, Memorial Sloan-Kettering Cancer Center and the Karmanos Cancer Institute.
"It's an exciting time for breast cancer research," says Anthony Elias, M.D., breast cancer program director at CU Cancer Center. "We should know soon if we have a viable new target in breast cancer treatment."
Read more about TNBC in my book, Surviving Triple-Negative Breast Cancer.