It is only suitable for a small minority (about 15 - 20%) of women with breast cancer. To be suitable your your cancer must have the Her-2 receptor. Like chemotherapy and hormone therapy it treats breast cancer that has (or potentially has) spread to other parts of the body.
It is an outpatient treatment given every 1 - 3 weeks by a drip directly into the bloodstream.
Treatment lasts about a year although duration of treatment is currently debated.
Common side effects are:
- Flu-like symptoms
Current guidance suggests that women receiving Herceptin should also be monitored for uncommon side effects on the heart with a regular heart scan (echocardiogram).
At the time of writing we only have evidence to say that Herceptin is effective in women who are also having chemotherapy.