Understanding Chemotherapy

Chemotherapy uses drugs to kill cancer cells. Chemotherapy is used to:

• Help cure some cancers
• Shrink a cancer before surgery, to make it easier to remove
• Kill any cancer cells that remain after surgery
• Help radiotherapy to work better
• Help stop cancer from spreading, slow its growth, or destroy cancer cells that have spread to other parts of your body
• Treat cancer that has come back after treatment

Chemotherapy drugs affect how a cancer cell divides and grows. Chemotherapy damages genes inside the cancer cell, preventing them from growing. 

Chemotherapy affects healthy cells too, but cancer cells are more sensitive to chemotherapy because they divide more frequently. 

Healthy cells usually repair the damage caused by chemotherapy but cancer cells cannot and so they eventually die.

Find out more

There are many types of chemotherapy drugs that can be given individually or in combination.

These combinations used by your doctor are often known by a word made up from the first letters of the drug names (an acronym).

Chemotherapy is given in different ways, depending on the cancer type and the drugs being used. It may be given to you through:

• A drip (intravenous infusion) into the bloodstream through a vein – drugs are diluted in a large bag of liquid and go in slowly over several hours.
• An injection into the bloodstream (usually through a vein). The drugs are injected into a drip by a nurse. It can last from a few minutes to 20 minutes.
• Tablets or capsules taken by mouth (oral therapies). Read more about oral therapies

Other, less common ways of giving chemotherapy:

• By injection into the fluid around the spine and brain (intrathecal chemotherapy)
• Directly into an organ, such as the liver
• Directly into a body cavity, e.g., the bladder (intracavity chemotherapy)
• Applied as a cream to the skin (topical chemotherapy)
• By injection into a muscle (intramuscular chemotherapy)
• Under the skin (subcutaneous chemotherapy)

Cancer drugs can be given directly into a vein using the following devices:

• Cannula – a short, thin tube is put into a vein in your arm or the back of your hand.
• Central line – a thin flexible tube is put in through the skin of your chest or neck and into a vein in your chest.
• PICC line (peripherally inserted central catheter) – a thin, flexible tube is put into a vein in your arm and then put in (threaded through) to a vein in your chest.
• Implantable port (sometimes called a portacath) – a thin, soft, plastic tube is put into a vein. It has an opening (port) under the skin on your chest.

We have more information on lines and ports and how to care for them.

Some chemotherapy, targeted therapy and immunotherapy drugs are taken my mouth, as a tablet or capsule. These are known as oral therapies.

After you take the drug by mouth, it is absorbed into your blood stream and carried around your body just like intravenous drugs. Oral therapies are just as effective as intravenous drugs.

Oral therapies are usually prepared in a special area of the hospital pharmacy. All the drugs are carefully checked by the pharmacy staff to make sure they are the right ones for you.

Read more on oral therapies