HER2-positive breast cancer

What does HER2 positive mean? 

HER2 is a protein that helps cancer cells to grow. HER2-positive cancers make too much HER2, so the cancer may grow more quickly. There are treatments that can target HER2, which are often good at keeping the cancer under control. 

Is it common for cancers to be HER2 positive? 

About 1 in 5 breast cancers is HER2-positive breast cancer.

How are HER2-positive cancers treated?

• Surgery. Surgery to remove the tumour is usually the first treatment for breast cancer, if it is possible. 

Treatment after surgery

You may have more treatment after surgery to try to reduce the risk of the cancer coming back. For example:

• Targeted therapies. If your cancer has a high number of HER2 protein receptors, you might have targeted therapies (for example, trastuzumab). These drugs block the HER2 receptors and stop the HER2 protein from helping the cancer to grow. You might have targeted therapies along with chemotherapy drugs. 
• Radiotherapy. Radiotherapy after surgery can help to reduce the risk of the cancer coming back. 
• Chemotherapy. If your cancer cells are high grade (fast growing) or were found in the lymph nodes, or if your tumour was very large you might have chemotherapy to reduce the risk of the cancer coming back. 
• Hormone therapy (anti-oestrogen drugs) If your cancer has hormone receptors that help the cancer to grow (oestrogen-receptor positive cancer), you may have hormone therapy drugs. These work to stop the hormones from helping the cancer to grow.