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.