What is HER2+ breast cancer?
Some people with breast cancer have a gene mutation that causes their cells to make too much of the HER2 (human epidermal growth factor receptor 2) protein. At higher-than-normal levels, HER2 protein promotes the growth of abnormal cells—this causes HER2+ breast cancer. Among people with breast cancer, about 20%—or about 1 in 5—have HER2+ breast cancer.


HER2+ breast cancer is different from other types of breast cancer, because it:
- Tends to be more aggressive
- Grows quickly
- Is more likely to come back or spread, even after other treatments
Until there is a cure for breast cancer, there is still a risk of the cancer returning.
What is early-stage HER2+ breast cancer?
Early-stage HER2+ breast cancer is breast cancer that has not spread beyond the breast or the lymph nodes under the arm. Though it is highly treatable, it can still return after chemotherapy, surgery, and trastuzumab-based treatment (for example, Herceptin®). Some risk factors that affect the chance of cancer returning in people include age, overall health, and tumor size or lymph node involvement.
The risk of recurrence in women with early-stage HER2+ breast cancer can be as high as 25% in 10 years. Taking extended adjuvant therapy (for example, NERLYNX) after trastuzumab-based treatment may help you do more to further reduce that risk.
*NERLYNX targets HER2+ cancer cells, but may also affect healthy cells.