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Chemotherapy and other drug therapies

Drug therapies work in different ways to destroy cancer cells, stop them from spreading or slow down their growth. Drugs may also be used to lessen, or relieve, side effects of cancer or its treatment.

  • Chemotherapy (sometimes called chemo) destroys cancer cells or slows down how fast they grow. Some chemotherapy drugs are given on their own. More often, several chemotherapy drugs are used together to destroy cancer cells.
  • Hormonal drug therapy changes the levels of certain hormones in your body to destroy cancer cells or slow down how fast they grow.
  • Immunotherapy helps to strengthen or restore the immune system’s ability to fight cancer.
  • Targeted therapy uses drugs to target specific molecules (for examples, proteins) in cancer cells to stop them from growing and spreading. Targeting cancer cells means that these drugs don’t damage as many normal cells.
  • Supportive drugs prevent, manage or relieve side effects that cancer or cancer treatments may cause. For example, bisphosphonates help strengthen bones and protect them against the effects of some cancers and their treatments.

Sometimes drug therapy is the only treatment you receive. You may need only one type of drug therapy, or you may receive a combination of drug therapies.

Goals of drug therapy

Your doctor will explain the goals of your treatment plan. As part of your treatment plan, drug therapy may be used in the following ways.

  • Drug therapy may cure the cancer by destroying all the cancer cells and reducing the chances that the cancer will come back.
  • It can control the cancer by stopping cancer cells from growing and spreading or destroying cancer cells that have spread to other parts of the body.
  • Drugs can prevent the growth or spread of new cancer cells.
  • They can relieve the symptoms of the cancer and help you feel more comfortable when curing the cancer is not possible.

Drug therapy and other treatments

Drug therapy may be used as the first-line therapy (the primary, most common or preferred treatment). It may also be used with other treatments as part of your treatment plan.

  • Drug therapies may be used as adjuvant therapy. This means that drug therapies are given in addition to the first-line therapy. The drugs destroy any cancer cells that are still in the body after surgery or radiation therapy and help reduce the risk that the cancer will come back (recur).
  • Sometimes drugs are given as neoadjuvant therapy. They are used to shrink a tumour before the first-line therapy. Shrinking the tumour makes it easier to remove with surgery or to treat with radiation.
  • Drug therapy given at the same time as other treatments is called concurrent therapy. For example, certain chemotherapy drugs may be given at the same time as radiation therapy to make cancer cells more sensitive to radiation.

immune system

The complex group of cells and organs that defend the body against infection, disease and foreign substances.


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