What to expect from HER2-targeted therapy for HER2-positive breast cancer

HER2-targeted medicines attach to HER2 signals on cancer cells or interfere with the signals that help those cells grow. Depending on your plan, treatment may be given through a vein or as an injection, alone or alongside chemotherapy, surgery or radiotherapy. Your team may check HER2 on tumour tissue before choosing treatment.

At visits, clinicians review symptoms, medicines and any changes in your health. Heart assessment may be arranged because some HER2-targeted medicines can affect heart function. Hair changes, tiredness, diarrhoea, nausea, fever or soreness can occur, particularly when another treatment is given at the same time.

Keep a record of symptoms between appointments, including bowel changes, breathlessness, swelling, fever and how long each symptom lasts. Take medicines exactly as prescribed and tell the team about heart disease, pregnancy, breastfeeding, allergies and every prescription, supplement or non-prescription medicine.

Eat and drink as advised by your oncology team, rest between activities and use the recommended skin or mouth care. Do not delay reporting a new symptom: early advice can help your team adjust supportive treatment or the appointment plan.

Contact your oncology team promptly for fever, chills, rash, wheezing, facial swelling, severe diarrhoea, repeated vomiting, unusual bleeding, new swelling or increasing tiredness. Seek urgent medical help for severe breathing difficulty, chest pain, fainting or sudden confusion, especially during or soon after an infusion or injection.

Ask which HER2 medicine you will receive, how it will be given, how long each visit may take, which heart checks are needed, which symptoms need same-day advice and how treatment fits with surgery, chemotherapy or radiotherapy.