Chemotherapy is the use of medicines to kill or reduce the spread of cancer cells. Chemotherapy is given as cycles and may be given once a day, once a week or even once a month. This depends on the type of cancer and the best regimen (course) as determined by research. Chemotherapy, unlike radiation (which treats only the part of the body exposed to the radiation), treats the entire body. As a result, any cells that may have escaped from where the cancer originated are treated.
A doctor who prescribes chemotherapy is known as a medical oncologist.
Depending on what type of cancer you have and whether it has spread, your doctor may use chemotherapy to:
- Eliminate all cancer cells in your body, even when cancer is widespread
- Prolong your life by controlling cancer growth and spread or
- Relieve symptoms and improve your quality of life.
Most chemotherapy drugs are given in one of the following ways:
- You might take a tablet or medicine orally (swallow)
- It may be given intravenously as an injection over a short period of time or as an infusion over a longer period of time. For these treatments you come into the Department usually for part of the day.
Some people have no side effects at all from chemotherapy. Sometimes, however, chemotherapy will make you feel sick. As each type of chemotherapy has different side effects they will be discussed with you prior to starting any treatment so you know what to expect. Chemotherapy targets cells that are quickly dividing, whether it's a cancer cell or not. Therefore, some non-cancer cells that divide quickly are also damaged. The following is a list of some normal cells that divide quickly in the body and may be susceptible to the effects of chemotherapy:
- Cells in your hair (can cause hair loss)
- Cells of the skin and mouth (can cause sores in your mouth and dry skin)
- Cells in your stomach and intestines (can cause you to feel sick, vomit or have diarrhoea)
- Cells in your bone marrow. This is where your red and white blood cells are made. White blood cells fight infections, so temporarily you are very prone to these and they can become serious. Loss of red blood cells can make you anaemic and tired.
There are many medicines you can take to reduce or lessen these unwanted effects of chemotherapy.
In some cases, chemotherapy may be the only treatment you need. More often, it's used in conjunction with other treatments, such as surgery or radiation, to improve results. For example, you may receive:
- Neoadjuvant chemotherapy. The goal of neoadjuvant therapy is to reduce the size of a tumour with chemotherapy before surgery or radiation therapy.
- Adjuvant chemotherapy. Given after surgery or radiation, the goal of adjuvant chemotherapy is to eliminate any cancer cells that might linger in your body following earlier treatments.