Immunotherapy is routinely used to treat some types of cancer, either on its own or alongside other treatments. So, what is immunotherapy? And how is it different from chemotherapy?
The main difference between chemotherapy and immunotherapy is that chemotherapy uses anti-cancer drugs to treat tumours. In contrast, immunotherapy enables your own immune system to recognise, target and destroy cancer cells.
What exactly is chemotherapy?
Chemotherapy is a widely used therapy, treating over 200 different types of cancer. It’s when you take medication, either intravenously or orally, to destroy tumours. It’s carried via your bloodstream and disrupts the inner workings of cancer cells, stopping them from growing and dividing. You might be given a single chemotherapy drug or a combination.
Immunotherapy works by empowering the immune system to attack cancer cells. This can be done by making cancer cells recognisable to the immune system, or by blocking the pathways that cancer cells use to hide from our natural antibodies. Some immunotherapies are known as targeted treatments.
You might be wondering why cancer cells aren’t already targeted by our natural defences. That’s because they can ‘hide’ from the immune system, either by escaping defensive cells or by producing signals that cause the immune system to ignore them. In some cases, aggressive cancer cells can also overwhelm the immune system. This means, even if they can be identified, they are still able to spread.
What about side-effects?
So, what about the differences in side-effects? Chemotherapy attacks all dividing cells, whether they are healthy or cancerous. This causes side-effects, including hair loss and nausea in some cases. Immunotherapy also has side-effects, but they’re different from other cancer treatments because they result from the immune system being over-activated or misdirected. The good news is that, in most cases, any side-effects get better after the first treatment. If necessary, they can be safely managed with drugs that suppress the immune system. But you need to let your medical team know straight away if you experience any side-effects because in some cases, they can be more severe or even life-threatening.
Which treatment is shorter?
How long you need treatment with either therapy is down to many factors, including the type of cancer and your general health. Chemotherapy can cause tumours to shrink quickly, while immunotherapy can take longer - but the results can be longer-lasting too.