DNA methylation predicts response of triple-negative breast cancer to all-trans retinoic acid treatment

We have identified a new approach to select breast cancer patients who will benefit from treatment with an existing drug, retinoic acid. This research will have important benefits for patients with an aggressive type of breast cancer known as triple-negative breast cancer (TNBC). TNBCs do not respond to three common growth signals - estrogen, progesterone, or the human epidermal growth factor - so they cannot be treated with many existing drugs such as tamoxifen, which targets the estrogen receptor, or Herceptin, which targets the Her2 protein. A complicating factor in the treatment of breast cancer patients is that breast tumors can be very different from each other. TNBC tumors can have different responses to drugs, which means we must determine which genetic factors affect how TNBCs respond to retinoic acid. We have already identified several genes which, when expressed at different levels, affect the response of TNBC tumors to retinoic acid. Our continued identification of these genetic factors will allow us to predict how patients with TNBC tumors will respond to retinoic acid therapy. This will allow the precise use of retinoic acid in the treatment of breast cancer.