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Macmillan and Cancerbackup merged in 2008. Together we provide free, high quality information for people affected by cancer through our publications, website and phone service. Find out more|.
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This information is about trastuzumab, which is commonly known as as Herceptin®. It may be used as to treat breast cancer| and stomach cancer|. It may also be used to treat other types of cancer as part of a cancer research trial|.
Herceptin is one of a group of cancer drugs called monoclonal antibodies|.
Monoclonal antibodies recognise and lock on to specific proteins on the surface of cancer cells. This helps the body's immune system recognise the cancer cells and destroy them. Monoclonal antibodies are sometimes called targeted therapies because they are designed to target cancer cells.
Herceptin works by interfering with one of the ways in which some cancer cells divide and grow.
Many types of cells in the body have proteins called growth factor receptors on their surfaces. When growth factors, which occur naturally in the body, lock on to these receptors the cells are stimulated to grow.
Some cancers have too much of a protein called human epidermal growth factor receptor 2 (HER2) on their surfaces. They are called HER2 positive cancers|. The extra HER2 receptors on HER2 positive cancers helps them grow.
Herceptin is designed to treat people with some types of HER2 positive cancers. It works by attaching to the HER2 protein on the cancer cells so that growth factor cannot reach the cancer cells. This stops the cells from dividing and growing. Herceptin also works by attracting the body’s own immune cells to help destroy the cancer cells.
Herceptin only works in people who have cancer with high levels of the HER2 protein.
Several tests are available to measure HER2 levels|. Testing can be done at the same time as initial cancer surgery, or samples of cancer cells from previous biopsies or surgery may be used.
It may be used in the early stages to increase the chances of a cure or in advanced stages to help control the disease if the breast cancer has come back.
Herceptin may be used in combination with chemotherapy to treat stomach cancer| that has spread beyond the stomach (metastatic or advanced gastric cancer).
Some other cancers also have high levels of the HER2 protein and research trials are currently underway to see if Herceptin may help in these cancers. Because Herceptin is a relatively new drug, it may not always be widely available on the NHS. We have more information on what you can do if a treatment isn't available|.
Herceptin is given by a drip into a vein (intravenous infusion). It can usually be given in the outpatient department at the hospital.
The first dose is given slowly, usually over about an hour and a half. After the first infusion, you'll need to stay in hospital for about 4-6 hours so the nurses can monitor you for any reaction to the Herceptin. If you have no problems with this, later infusions will normally take about 30 minutes. You'll be able go home soon after they finish.
Herceptin may be given once a week or once every three weeks. If it's given together with chemotherapy drugs, they are given in the normal way, which is usually every three weeks.
Each person's reaction to a cancer drug is different. Some people have very few side effects while others may experience more.
We've outlined the most common side effects but haven't included those that are rare and therefore extremely unlikely to affect you. If you notice any effects that aren't listed below, discuss them with your doctor or nurse.
Side effects of Herceptin fall into two groups:
These may include a headache, high temperature (fever) and chills, feeling sick (nausea) or being sick (vomiting).| These symptoms can be controlled or reduced with medicines, which your doctor can prescribe for you. They generally get better within a few hours of the infusion finishing.
This is uncommon. Signs may include a skin rash, itching, wheezing, difficulty breathing and breathlessness. You'll be closely monitored during your treatment, but let your nurse or doctor know if you have any of these symptoms. Antihistamines can be given before the infusion to reduce the chance of an allergic reaction.
This can usually be controlled with medicine, but let your doctor know if it's severe or if it continues. It's important to drink plenty of fluids if you have diarrhoea|.
Herceptin may lead to some people having heart problems. It's recommended that Herceptin is not given to people with a history of heart disease or high blood pressure.
In order to check your normal heart function, you will have tests (usually an echocardiogram) before starting treatment with Herceptin.
If Herceptin is given in combination with chemotherapy, you'll also experience the side effects of the chemotherapy drug|.
It's important to let your doctor know straight away if you feel unwell or have any severe side effects, even if they're not mentioned above.
This section is based on our Trastuzumab fact sheet and has been compiled using information from a number of reliable sources including:
For answers, support or just a chat, call the Macmillan Support Line free (Monday to Friday, 9am-8pm)
If you have any questions about cancer, need support or just want someone to talk to, ask Macmillan.