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Chemotherapy (chemo) is the use of drugs to fight cancer. The drugs may be put into a vein or given by mouth. These drugs enter the bloodstream and travel throughout the body, making this treatment useful for cancers that have spread to distant organs.

Chemo is sometimes used before surgery to try to shrink the cancer and make the surgery easier. It may also be given after surgery to lower the chance of the cancer coming back. Chemo can also help relieve symptoms of advanced cancer and help some people live longer.

Chemo is sometimes given along with radiation. This is called chemoradiation. The chemo helps the radiation work better, but adds to the side effects. This can be given before or after surgery for rectal cancer.

In some patients, chemo drugs can be put into an artery leading to the part of the body with the tumor. This approach is called regional chemotherapy. Since the drugs go straight to the area with the cancer, there may be fewer side effects. Regional chemotherapy is sometimes used for colon cancer that has spread to the liver

Side effects of chemo

While chemo kills cancer cells, it also damages some normal cells and this can cause side effects. These side effects will depend on the type of drugs given, the amount given, and how long treatment lasts. Common side effects could include:

  • Diarrhea
  • Hair loss
  • Mouth sores
  • Loss of appetite
  • Nausea and vomiting
  • Increased chance of infection (from low white blood cell counts)
  • Easy bleeding or bruising after minor cuts or injuries (from low levels of platelets, which help the blood clot)
  • Severe tiredness (fatigue) (from low levels of red blood cells)

There are also some side effects that only happen with certain drugs. For example, some drugs can cause something called hand-foot syndrome, where the palms of the hands and the soles of the feet get red and irritated and may even blister or develop open, painful sores. Some drugs can cause nerve damage which can be painful. Ask your doctor what you can expect with the drugs you will receive.

Most side effects go away when treatment is over. Anyone who has problems with side effects should talk with their doctor or nurse, as there are often ways to help.

More detailed information about chemotherapy for colorectal cancer can be found in Colorectal Cancer.

To learn more about chemo, see A Guide to Chemotherapy.

Last Medical Review: 10/15/2014
Last Revised: 02/26/2016