What does HER2-targeted therapy treat?

HER2 is a protein on the surface of some cancer cells. When testing shows that a tumour has too much HER2, medicines can attach to that protein or interrupt its growth signal. This can slow or destroy HER2-positive cancer cells while treatment is given.

The approach is used most often for HER2-positive breast cancer, and it can also be considered for some stomach cancers. Treatment may be given before surgery, after surgery, for advanced disease, or alongside another systemic treatment, depending on the tumour and its stage. A pathology report and medical assessment determine whether the target is present.

Ask whether your biopsy or surgical specimen included HER2 testing and what the result means. Your oncology team may discuss an antibody drug, a medicine that enters the cell, or an antibody-drug conjugate such as those described in Antibody-Drug Conjugates. The plan can change if the cancer returns or spreads.

Keep a record of new symptoms and medicines. Tell the team about heart problems, breathing symptoms, pregnancy plans, and previous cancer treatments before therapy starts. HER2-targeted medicines may be combined with chemotherapy, surgery, radiotherapy, or another targeted drug.

Contact your oncology team promptly for new breathlessness, chest discomfort, fainting, marked swelling, fever, or an infusion reaction such as flushing, wheezing, or sudden dizziness. These symptoms can have several causes, but they need timely assessment during treatment.

Is my cancer HER2-positive, and which test established that result? Which HER2-targeted medicine is being considered? Will treatment be given before or after surgery, and how will heart function or other possible effects be monitored?