]]>Chemotherapy]]> uses drugs to kill cancer cells. The drugs enter the bloodstream and travel through the body in order to kill cancer cells. The side effects from the chemotherapy come from the fact that it destroys normal cells as well. Chemotherapy may be given either alone or along with ]]>radiation therapy]]> . When given alone, it is given in a higher dose designed to kill off cancer cells. When given along with radiation therapy, it is delivered at a lower dose and is designed to make the cancer more sensitive to the radiation.

The most common agents used are 5FU and folinic acid. Newer agents designed to inhibit tumor blood vessel growth are also being used for patients with advanced stage and metastatic colon cancer. Ask your doctor which agents are most appropriate for your treatment.

Chemotherapy is usually given by vein, but some forms can be given by mouth. Your medical oncologist will tell you how many cycles or courses of chemotherapy are best for you.

There is some debate about how many cycles of chemotherapy are used in the treatment of colon and rectal cancer. Generally, when patients get chemotherapy alone for colon or rectal cancer (after surgery), they receive between 6-12 cycles. When it is given along with radiation therapy, the patient may get two cycles alone, and then two more cycles with the radiation therapy, and then another 4-8 cycles after the radiation therapy is done. Different schedules are used by different oncologists. Discuss your exact plan with your doctor. There are also different schedules depending on the types of drugs used. You may also want to ask you doctor if you are an appropriate candidate for chemotherapy research trials.

The side effects and amount of time required in the doctor’s office depend on the type of chemotherapy you receive, as well as how many cycles you receive and how often. The most common chemotherapy-associated side effects are:

  • Nausea and vomiting
  • Fatigue or tiredness
  • Confusion, forgetfulness (“chemo brain”)
  • Decreased blood counts, sometimes with bruising, bleeding, or infection
  • Possible sores inside the mouth
  • Numbness in the hands and feet
  • Diarrhea, loose stool
  • Increased urgency to have a bowel movement or urinate

When chemotherapy is given at a lower dose, as when it is given along with radiation, these side effects are less common. However, most people still feel fatigued. Other side effects, such as irritation of the colon and anus (]]>colitis]]> , proctitis) may be more likely or more severe due to the combination of treatments. Patients with a history of colitis, ]]>Crohn’s disease]]> , and other gastrointestinal problems should be sure to alert their doctor of these conditions before treatment is started.

A variety of drugs is available to help manage side effects such as nausea and vomiting, diarrhea, and fatigue due to anemia. Ask your doctor what treatments may be appropriate for you to manage these side effects, and be certain to contact your physician as soon as you begin to experience side effects. The earlier side effects are addressed, the more likely they will be controlled with a minimum of discomfort.