Biological Therapies / Targeted therapies

Biological therapies can be more specific and target the parts of cancer cells that make them different from normal cells. That´s why we also use the term “targeted´ therapies for some of them.

You probably know about chemotherapy where drugs are used to kill cells that divide and grow quickly. Chemotherapy works on cancer because cancer cells divide quickly and the chemotherapy will therefore try to kill those fast-growing cells. But some of the normal cells in our bodies are also fast-growing so the chemotherapy will kill those cells too because the chemotherapy drugs can’t tell the difference between a cancer cell and a normal cell if they behave in a similar way. Biological therapies work differently as they can be more specific and target the parts of cancer cells that make them different from normal cells. That’s why we also use the term “targeted’ therapies. So both chemotherapies and targeted therapies try to find and kill cancer cells but they use different methods for identifying which cells they are meant to kill.

Sometimes targeted therapies may not attack the cancer cells themselves but target other cells that help cancer cells grow. If the treatment can kill those ‘helper’ cells, it will be difficult for the cancer cells to survive. For example when­ cancer cells divide and make more cancer cells that grow into a lump (tumour), the cancer lump needs oxygen to survive and continue growing. The oxygen is delivered to the cancer cells via a network of blood vessels surrounding the tumour. With targeted therapy, drugs can be given to target and destroy those blood vessels so that the cancer doesn’t get the oxygen it needs to survive.

Another type of biological treatment is called “immunotherapy”. This is when drugs are given to make the immune system stronger and more effective. The most important job of the immune system is to protect our body from infections but it can also help to protect against cancer. The immune system very cleverly keeps track of all the substances that we normally have in our bodies. So if the immune system discovers any abnormal substances – such as germs – it will attack them to try and get rid of them. Cancer cells are also abnormal substances but because they have developed from normal cells, they are often not different enough for the immune system to discover them and get rid of them. Sometimes though, the immune system does discover the cancer cells but the immune system might not be strong enough to destroy them. Therefore, it is important to find drugs that can either ‘boost’ the immune system to become stronger and more effective or train the immune system to be better at discovering the cancer cells and attack them.

At the moment, these types of treatments are not suitable for all types of cancers because they may attack / target specific parts of some types of cancer cells but not other types. There is a lot of research going on to find more drugs so that more cancers can be treated with some form of targeted therapies, often in combination with other types of cancer treatments.

To help you find out more, we have linked to Maggie’s CancerLinks where you will be signposted to high quality information about different types of cancer treatments.

Please get in touch with us if you have any worries or questions related to cancer.

Page updated 17 July 2017