Breast cancers that initially respond to hormone therapies, like tamoxifen, eventually become resistant to treatment. A new study finds this may be because of a mutation in the receptor present in the cancer cell to which tamoxifen binds.
“We identified a new mutation in the estrogen receptor, which is the target for endocrine treatments, and the mutation makes the receptor more active and resistant to endocrine treatments. Importantly, we identified the mutation in 38 percent of our patients. Thus, our findings may be relevant to many of the patients who develop resistance,” Ido Wolf, MD, head of the medical oncology department at the Tel Aviv Sourasky Medical Center in Israel, was quoted as saying.
Researchers say that they now need to find ways to inhibit this mutated receptor and develop therapies that will be more effective and less toxic than chemotherapy.