Chemotherapy is a key therapy for patients diagnosed with cancer. It can be used on its own or in conjunction with other treatments such as surgery or radiotherapy. Chemotherapy is a type of ‘systemic’ therapy, where it travels to various organs and tissues via the bloodstream. Other, newer systemic therapies include immunotherapies and targeted therapies.
The primary aim of chemotherapy is to shrink an existing tumour or remove cancerous cells from the body. Administering chemotherapy as part of the cancer treatment aims also to reduce the chances of the cancer spreading, known as metastases, where cancer cells are found in other tissues and organs in the body from where they first arose. Where it is used to shrink an existing tumour prior to surgery, it is referred to as 'neoadjuvant therapy', and where it is used after the main treatment, it is referred to as 'adjuvant therapy'.
It can also be used on a low dose basis to extend a period of remission ('maintenance chemotherapy'), or where cancer has reached a later stage, to increase life expectancy and to decrease the impact of the tumour/s on the body ('palliative chemotherapy').
How chemotherapy works
Cancer cells divide more rapidly than most other cells in the body, and the chemotherapeutic agents target these rapidly dividing cells. Unfortunately, some normally rapidly dividing cells in the body, such as hair cells, blood cells and some cells in the gastrointestinal tract, can also be affected by chemotherapy, causing common side effects such as hair loss, general tiredness and conditions that affect the digestive tract such as nausea and vomiting, loss of appetite and constipation or diarrhoea. Although these side effects are common, not everyone that goes through chemotherapy has these side effects, and some people have none.
The type of treatment you receive will depend on the type of cancer you have and the stage it is at. Chemotherapy is generally administered intravenously (i.e. injected slowly via a vein), although some chemotherapy is administered by mouth, or in some cases applied directly to affected tissue in the body. A chemotherapy course (referred to as a 'cycle') can last anything from a few days to weeks, generally with short breaks in between treatments to allow the body to recover.
During chemotherapy treatment you will be monitored to see how well the treatment is working. If necessary, different chemotherapeutic agents may be used, either together with the original agent/s or as a replacement for it / them.