Targeted therapy drugs are used to treat a number of different cancers. Some of these drugs can affect the heart.
Trastuzumab is given to reduce the risk of breast cancer coming back in women who have HER2 positive breast cancer. It’s also used to treat advanced HER2 positive breast cancer.
In some women, trastuzumab weakens the heart muscle, which means the heart can’t work as well as it did before (heart failure). It may not cause any symptoms, but in more severe cases, it can lead to breathlessness, chest discomfort and fatigue. The risk of trastuzumab causing heart problems increases if a woman is overweight.
You will have tests, such as an ultrasound of the heart (echocardiogram) to check your heart function before starting treatment with trastuzumab, and at regular intervals during treatment. If your heart function changes, your treatment may be stopped temporarily and you may be referred to a cardiologist. Your treatment may be restarted once your heart function has improved or returned to normal.
Women with existing heart problems are not usually given trastuzumab, as they are more likely to develop serious heart problems with treatment.