When your breast cancer cells are tested by the pathologist they will be tested to see if they have certain ‘receptors’. Our basic non-medical understanding is that certain levels of certain receptors can stimulate the cancer to grow. For a more detailed explanation of receptors, you can read this Macmillan guide.
One of the receptors for which they test is HER2.
If your breast cancer has a certain level of these HER2 receptors, you have what is called HER2 positive breast cancer (HER2+ve). The proportion of women with this diagnosis is fairly small (around 15% of breast cancer cases according to Macmillan).
A drug called Trastuzumab is given to women with HER2 positive breast cancer. Here is our bullet point list of things to know about being HER2+ve and having this treatment:
1. Trastuzumab is the generic name for this drug but it goes by different brand names. In the UK it is most commonly known by “Herceptin”. You will generally hear people say that they are “having Herceptin”.
2. Trastuzumab is not a chemo drug. It is a “biological therapy”. This means that it targets the HER2+ve receptors on the cancer cells and destroys them that way.
3. Depending on your treatment plan and hospital, you will be given this drug every three weeks for certain period of time (Sara had it for a year). It is given either by IV or a subcutaneous injection (which is an injection usually into the thigh and they alternate between the left and right thigh).
4. If you’re given it via an injection, the injection is given slowly over the period of a few minutes. It can sting very slightly when it goes in while the drug is absorbed into the subcutaneous tissue of your thigh. Sara says that she felt a little sting. A nurse gives the injection so if it stings you can ask the nurse to slow the injection down.
5. Before you have your first dose of the drug, you have your heart checked out by having an echocardiogram (click here to read about these on the NHS website). The chances are you will already have had one of these along your cancer road, but it if you haven’t then it is nothing to worry about – it is basically an ultrasound of your heart which is done by a nurse holding a sensor on your chest and looking at the image of your heart on a monitor. The reason for having your heart checked out is because there is a small chance of a side effect affecting your heart. This also means that for the year of Trastuzumab treatment you will probably have regular echocardiograms. The frequency of these will depend on your hospital policy.
6. The first time that you are given Trastuzumab you have to stay at the hospital for a few hours to be monitored for side effects. You may be given your first dose when you go in for one of your chemo cycles. Or your Trastuzumab treatment may start after your chemo treatment ends.
7. Trastuzumab is generally (although it differs for each patient) not like chemo in causing lots of side effects. There are some, which your oncologist will tell you about, but on the whole having the Trastuzumab injections is quick, painless and straightforward. I could drive myself to the hospital, have the injection, go home and carry on the day as normal. For information on the drug and possible side effects, take a look at the Breast Cancer Now website page.
8. Sara noted that on some occasions (not all) the injection site on her leg raised up into a small lump, and then she had a red patch for a week or so. She felt no discomfort and the nurses told her that this was a common side effect and she shouldn’t worry about it.
If you want to know how Herceptin works take a look at this page on the Cancer Research UK website.
The Breast Cancer Now booklet can be ordered or downloaded here.
For information on the drug and possible side effects, take a look at the Breast Cancer Now website.
The information and content provided on this page is intended for informational and educational purposes only and is not intended to substitute for professional medical advice.
Reviewed August 2020
Sylvie and Danielle began Future Dreams with just £100. Since then we have raised over £6.5m. We couldn’t do any of this without you. Please donate, if we all act now we believe that by 2050 everyone who develops breast cancer will live.