When your breast cancer cells are tested by the pathologist they will be tested to see if they have certain “receptors”. My basic non-medical understanding is that certain levels of certain receptors can stimulate the cancer to grow. One of the receptors for which they test is HER2.
If your breast cancer has a certain level of these proteins, 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 my 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. I had it for a year. It 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. The injection is given slowly over the period of a few minutes. It can sting very slightly when it goes in whilst the drug is absorbed into the subcutaneous tissue of your thigh – but honestly, for me, it was completely fine and a little sting is nothing compared to everything else we have to go through. 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 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 need to have an echocardiogram every 10 weeks.
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. On some occasions (not all) the injection site on my leg raised up into a small lump, and then I had a red patch for a week or so. I felt no discomfort. the nurses told me that this was a common side effect and I shouldn’t worry about it. So I didn’t.
HELPFUL RESOURCES AND MORE INFORMATION
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.