HER2-positive breast cancers have a high level of protein called HER2 on the surface of their cells. The HER2 protein is an important part of the pathway for cell growth and survival.

All breast cancers are tested for HER2 status. About 10 to 20% of newly diagnosed breast cancers are HER2-positive. These cancers can be treated with drugs that specifically target the HER2 protein.

HER2-targeted therapies for early and locally advanced breast cancer include trastuzumab, known as Herceptin; ado-trastuzumab emtansine, or Kadcyla; pertuzumab, which is Perjeta and neratinib, also known as Nerlynx.

Before you begin treatment with any of these therapies, talk with your health care team about possible side effects and how to manage them.

For more information, visit the HER2-Targeted Therapies page within the Treatment section of komen.org.