Frequently Asked Questions
What is HER2?
HER2 stands for Human Epidermal growth factor Receptor type 2. HER2 is a protein that exists on the surface of all normal cells sending messages to the cells to grow and multiply. Sometimes breast cells have too much HER2 protein. This can cause them to grow much faster and turn from a normal cell into a cancer cell.
What does HER2-positive mean?
HER2-positive cancer is an aggressive form of cancer. When too much HER2 is expressed on the outside of some of your cells, these cells become ‘abnormal’. The abnormal cells start multiplying rapidly and producing more abnormal cells. This group of abnormal cells is termed a tumour. Cancers with too many copies of the HER2 gene or too many HER2 receptors tend to grow quickly and are thought to be more aggressive.
How do I know if my breast cancer is HER2-positive?
Your specialist will have sent a sample of your breast cancer cells (obtained during biopsy or surgery) to a pathology laboratory for a HER2 test. Ideally your specialist will have done this at the time of your diagnosis, but stored samples can also be tested.
Who should have a HER2 test?
All women with newly-diagnosed breast cancer or a new breast cancer recurrence should be routinely tested for HER2. About one in four (20 to 30%) women with breast cancer are HER2-positive.
Why is testing for HER2 status important?
HER2-positive breast cancer is a distinct and particularly aggressive form of breast cancer that progresses rapidly, responds poorly to chemotherapy and is associated with a high risk of relapse and shortened survival time. Knowing your HER2 status is critical in identifying the most appropriate treatment for you.
How do you test for HER2 status?
HER2 status is determined by testing breast cancer cells obtained during biopsy or surgery using the following laboratory tests:
immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH).
What is an immunohistochemistry (IHC) test?
Immunohistochemistry (IHC) measures HER2 protein levels on the surface of the cell. Results are scored as 0 or 1+ (HER2-negative), 2+ (borderline) or 3+ (HER2-positive). If your sample scored 2+, it would have been retested using FISH to accurately determine your HER2 status.
What is a FISH test?
Fluorescence in situ hybridisation (FISH) measures the number of copies of the HER2 gene. Results are either negative (HER2- negative) or positive (HER2-positive).
What is Herceptin?
Herceptin contains the active ingredient trastuzumab (pronounced traz-too-za-mab) and is an anticancer therapy for women with HER2-positive breast cancer. Herceptin is designed to target HER2 proteins on breast cancer cells to help your body’s immune system fight the cancer.
How is Herceptin different from other therapies?
Herceptin belongs to a class of anticancer treatments known as monoclonal antibodies.
A monoclonal antibody is a type of biological therapy derived from the body’s natural immune defences. Unlike conventional treatments, such as surgery, radiotherapy and chemotherapy, Herceptin only targets cancer cells that overexpress HER2.
How does Herceptin work?
Herceptin stops the growth and multiplication of breast cancer cells by binding to HER2 proteins and blocking signals telling the cells to grow. Herceptin can also activate the immune system to kill HER2-positive cancer cells.
When Herceptin binds to HER2 proteins on the cancer cell, the immune system identifies the cell as a foreign object, attacks and kills the cancer cell. Herceptin can also enhance the effectiveness of chemotherapy which attacks and damages the DNA in cancer cells causing cell death.
Who may benefit from Herceptin?
Herceptin is only suitable for women with HER2-positive breast cancer; HER2 status must be confirmed by a HER2 test. Herceptin can be used either alone or in combination with other cancer treatments and can be of substantial benefit to women with HER2-positive breast cancer, regardless of the stage of their disease. All women with HER2-positive breast cancer should be considered for treatment with Herceptin.
How successful is Herceptin in treating early breast cancer?
Four clinical trials involving about 12,000 women with HER2-positive early breast cancer have consistently shown a highly significant survival benefit with Herceptin. Women who received Herceptin lived longer and had a significantly smaller chance of the breast cancer coming back than those who did not receive Herceptin.
How successful is Herceptin in treating metastatic breast cancer?
Herceptin has been used in the treatment of HER2-positive metastatic breast cancer since 1998. In clinical trials, women who received Herceptin in combination with chemotherapy lived longer and with a better quality of life than women who received chemotherapy without Herceptin. Herceptin also reduced the size of the tumour and delayed tumour growth.
How will I know if Herceptin is working?
Your specialist will monitor your progress in a number of ways. Evidence that Herceptin may be working could include improvements in a specific symptom such as pain, shrinkage of a lump on examination, improvements in a blood test or evidence from repeat X-rays and CT or MRI scan
How is Herceptin administered?
Herceptin is given by a drip (slow infusion) through a fine tube (cannula) inserted into a vein. This usually takes place within a cancer department at the hospital or clinic. You may receive Herceptin by itself or in combination with other breast cancer treatments. Your specialist will decide which treatment regimen is best for you.
How long will I be on Herceptin?
Your specialist will decide how long you should receive Herceptin based upon your response to treatment and the stage of your cancer. If you have early breast cancer you will usually receive Herceptin for 1 year. If you have advanced or metastatic breast cancer you will normally receive Herceptin up until your breast cancer progresses, or you are no longer benefiting from treatment.
Your treatment may also be stopped if you experience side effects that do not allow you to continue therapy. Your specialist will discuss this with you.
How frequently will I be given Herceptin?
Herceptin is normally given once every week or once every three weeks. Your specialist will decide which treatment regimen is best for you.
How long will the infusion take?
The first infusion of Herceptin will be given over a 90-minute period. After the infusion you will need to stay for a short time to make sure that you don’t have a reaction to the Herceptin.
Subsequent infusions will be given over a 30-minute period if you receive Herceptin on a weekly basis, or over a 90-minute period if you receive Herceptin once every three weeks.
The infusion may take longer if it is slowed or interrupted, if you experience side effects or have an allergic reaction.
Can I drive after the Herceptin infusion?
Herceptin does not generally cause any problems with your ability to drive or operate machinery. However, Herceptin can cause side effects such as chills and light-headedness, particularly after the first infusion. Do not drive until these symptoms have cleared or until you know how Herceptin affects you.
What are the possible risks of Herceptin therapy?
Herceptin can cause heart problems such as congestive heart failure. Symptoms of heart failure include shortness of breath, difficulty breathing and swelling of the feet or lower legs. These symptoms are usually temporary, can be managed during continued Herceptin therapy and resolve in most cases when Herceptin is stopped.
If your doctor thinks that your heart is being affected by treatment, they may want to suspend or even stop your Herceptin treatment for a while. The effects on the heart associated with Herceptin are different from chemotherapy and are often reversible, and your doctors may resume Herceptin therapy when your heart has returned to normal.
Herceptin can also affect the lungs, causing severe or life-threatening breathing problems that require immediate medical attention. Your specialist will have carefully assessed the benefits and risks of Herceptin therapy before deciding to treat you with Herceptin.
What side effects can occur during treatment with Herceptin?
Herceptin is not a chemotherapy, but like all medicines it does have side effects. Your specialist may prescribe medication to prevent side effects from occurring while you receive the Herceptin infusion. The most common side effects of Herceptin are fevers or chills occurring during the first infusion. Other common side effects include nausea, vomiting, pain, stiffness, shaking, headache, cough, dizziness, weakness and skin rash. These side effects are usually mild to moderate and occur less frequently with subsequent infusions.
Is there anything I can do to manage side effects?
Tell your specialist or other healthcare professional as soon as you experience any side effects from treatment. You may receive medication to treat your symptoms or your Herceptin infusion may be slowed or interrupted to help control any side effects.
Will my hair fall out during Herceptin therapy?
Herceptin is generally well tolerated and not associated with side effects typically seen with chemotherapy, such as hair loss, severe nausea and vomiting and increased risk of infection. However, if you receive Herceptin in combination with chemotherapy you will also experience the side effects of the chemotherapy drug you are treated with.
Are there any symptoms that I should notify my specialist about immediately?
If you notice any of these reactions, seek medical help immediately:
- high temperature or fever
- sudden rash, itching or hives on the skin
- sudden swelling of the face, lips, tongue or other parts of the body
- sudden shortness of breath, wheezing or trouble breathing
- severe coughing
- chest pain spreading out to the arms, neck, shoulder and/or back
- abnormal/irregular heartbeat
- severe diarrhoea or vomiting
- feeling faint
- severe skin infections, including a bright red rash on the face or legs
Tell your specialist if you notice anything else that is making you feel unwell, even if it isn’t on this list.
Please do not be alarmed by this list of possible side effects – it’s important you know what they are. This isn’t a complete list of all the possible side effects. Others may occur in some people and there may be some side effects that are not known about yet.