What are the treatment options for HER2-positive breast cancer?

HER2 is a protein that can help breast cancer cells receive growth signals. A HER2-positive result means the cancer has an amount or activity of HER2 that may be addressed with HER2-targeted medicines. The result comes from testing the tumour tissue and is interpreted with its size, lymph-node findings, hormone-receptor status, and whether it has spread.

Chemotherapy medicines travel through the bloodstream and may be combined with HER2-targeted therapy. Treatment before surgery can shrink a tumour and provide information about how it responds. Treatment after surgery may reduce the chance of remaining cancer cells. For advanced disease, the team may use medicines to control cancer and symptoms over time.

Ask for a clear explanation of your HER2 test and whether hormone-receptor results change the plan. Discuss the order of medicines and surgery, expected monitoring, fertility and pregnancy considerations, and heart health checks when relevant to the chosen medicine. Tell the team about previous heart problems, breathlessness, other medicines, and any plans for pregnancy. Keep a record of treatment dates and symptoms so the team can adjust supportive care.

Contact the oncology team promptly for fever, chills, worsening breathlessness, chest discomfort, fainting, persistent vomiting, or an inability to drink. A new rash, swelling, severe diarrhoea, or marked weakness also deserves timely advice. Seek emergency care for severe breathing difficulty, sudden chest pain, or collapse.

What did my HER2 test show? Is treatment planned before surgery, after surgery, or both? Which medicine combination is recommended and why? How will heart health and other side effects be monitored? How could treatment affect fertility or pregnancy?