Breast cancer that has spread to the lymph nodes may change receptor status in the process—from estrogen-negative, for example, to estrogen-positive. One-third of the 211 tumors studies changed form, according to research published in the Annals of Oncology.
Researchers at the Breakthrough Breast Cancer Research Unit at the University of Edinburgh found that 82 of the tumors that had spread from the breast to the lymph nodes changed receptor status. Of these, 20 changed from estrogen negative to estrogen positive.
The implications of this are significant—some women with an original TNBC diagnosis, for example, might end up benefitting from tamoxifen or Arimidex. Researchers suggested additional tests be done on tumors that have spread to the lymph nodes.