For many years, doctors relied on a breast tumor’s hormone and HER2 protein receptor status to select the appropriate therapy, says Memorial Sloan-Kettering breast surgeon Tari King. Breast tumors with these characteristics can be treated with targeted therapies, such as tamoxifen or Herceptin®.
But up to 15 percent of breast cancers do not have receptors for estrogen, progesterone, or HER2, says Larry Norton, Deputy Physician-in-Chief for Breast Cancer Programs. These cancers, called triple-negative breast cancers, do not respond well to chemotherapy or other therapies. Surgical pathologist Jorge Reis-Filho says that researchers have the tools to uncover the genetic defects that drive tumor growth in women with triple-negative breast cancer and to develop additional targeted treatments.