Studies have shown that Herceptin attaches to HER2 receptors. Herceptin may stop a HER2 receptor from telling the cell to grow and divide. Also, Herceptin may signal the body’s immune system to destroy that cancer cell.Herceptin is approved for the treatment of early breast cancer (EBC) that is Human Epidermal growth factor Receptor 2-positive (HER2+) and has spread into the lymph nodes. In the case of HER2+ EBC that has not spread to the lymph nodes, it must meet the following condition: the cancer needs to be estrogen receptor/progesterone receptor (ER/PR)-negative or have one high-risk feature.* Herceptin is also approved for the treatment of HER2+ breast cancer that has spread to other parts of the body (metastatic breast cancer).
*High risk is defined as ER/PR-positive with one of the following features: tumor size >2 cm, age >35 years, or tumor grade 2 or 3.