Existing drug could prevent triple-negative breast cancer’s tumor growth. The scientists may soon test the drug estradiol in phase II clinical trial.
Triple-negative breast cancer, sometimes abbreviated TNBC, is an aggressive form of breast cancer that does not express the genes for three proteins. The three includes progesterone receptor (PR), estrogen receptor (ER), and human epidermal growth factor receptor 2 (HER2).
This cancer accounts for approximately 15%-25% of all breast cancer cases. Triple-negative breast cancer often requires combination therapies because its cells lack hormone receptors.
Now, researchers have found that an existing drug could prevent triple-negative breast cancer’s tumor growth. They say the drug could be reused in the treatment.
Researchers led by John Hawse, Ph.D., a molecular biologist at the Mayo Clinic in Rochester, MN, conducted a new experiment to test the effects of estradiol on the growth of triple-negative tumors. The findings of their research were published in the journal Proceedings of the National Academy of Sciences.
Hawse and his colleagues examined the effect of estradiol on the form of triple-negative breast cancer tumors.
“Remarkably we discovered that estradiol, which normally stimulates the growth of cancer cells in tumors that express estrogen receptor alpha, has the opposite effect in triple-negative breast cancer,” claims Hawse. “However, estradiol was only able to inhibit the growth of triple-negative breast cancer when estrogen receptor beta was present.” he said.
“Estradiol is Food and Drug Administration-approved as a treatment for women with breast cancer,” says study co-author Dr. Matthew Goetz, a medical oncologist.