Radiation Therapy for Colon, Rectum and Anus Cancers
Facts About Colon, Rectum and Anus Cancers
- This year, 108,000 Americans were diagnosed with colon cancer. Another 41,000 men and women were diagnosed with rectal cancer. About 5,000 people learned they had anal cancer.
Treating Colon, Rectum and Anus Cancers
- The primary treatment for colon cancer is surgery. Your doctor may also recommend radiation therapy and/or chemotherapy, depending on the location and stage of your cancer.
- For some rectal cancers, radiation therapy is given with chemotherapy to make the tumor smaller so it can be removed more easily during surgery. Other times, radiation is given after surgery to keep the cancer from returning.
- Anal cancer can often be treated with radiation therapy and chemotherapy, without surgery.
Understanding Radiation Therapy
- Radiation therapy, sometimes called radiotherapy, is the careful use of radiation to treat cancer safely and effectively.
- Cancer doctors called radiation oncologists use radiation therapy to try to cure cancer, control cancer growth or relieve symptoms, such as pain.
- Radiation therapy works within cancer cells by damaging their ability to multiply. When these cells die, the body naturally eliminates them.
- Healthy cells are also affected by radiation, but they can repair themselves in ways cancer cells cannot.
External Beam Radiation Therapy
External beam radiation therapy involves a series of daily outpatient treatments to accurately deliver radiation to the area needing treatment. The radiation beam usually comes from a machine called a linear accelerator.
- Before beginning treatment, you will be scheduled for a simulation to map out the area to be treated. This will involve having X-rays and/or a CT scan. Landmarks placed on your skin (often tiny tattoos) allow the radiation therapists delivering your treatments to precisely position you each day.
- To minimize side effects, the treatments are given gradually over about six weeks, five days a week (Monday through Friday). This allows your doctors to get enough radiation into your body to kill the tumor cells while giving healthy cells time to recover each day.
- Technical terms that may be mentioned for colorectal and anal cancer treatments include three-dimensional conformal radiation therapy (3D-CRT), intensity modulated radiation therapy (IMRT) or image guided radiation therapy (IGRT). Your radiation oncologist can provide more information on these different techniques.
- More about external beam radiation therapy
Treating Liver Metastases
Colon and rectum cancers sometimes spread to the liver.
- Liver metastases can sometimes be removed by surgery.
- When surgery is not possible, radiation therapy may be an option. A specialized external beam radiation treatment called stereotactic body radiation therapy (SBRT) can accurately target some liver tumors.
- Another treatment option is selective internal radiation therapy (SIRT), an injection of radioactive particles into the blood vessels of the liver.
- Your radiation oncologist can discuss with you which approaches are best in your case.
Possible Side Effects
- Radiation therapy to the abdomen may cause more frequent bowel movements, occasionally with diarrhea, abdominal cramping or rectal discomfort.
- Some patients may also feel tired or lose their appetite, this is temporary too.
- Possible skin irritation problems depend on your tumor and the areas needing treatment. For anal cancer patients, a pronounced but temporary skin irritation is usually the major side effect from the treatment.
- Side effects that occur are not the same for all patients. Ask your doctor what you might expect from your specific treatment program.
- It is likely you will receive chemotherapy in addition to radiation therapy. The side effects from the chemotherapy will depend on the drugs being prescribed and how often you are to receive them. Ask your medical oncologist about chemotherapy side effects you may experience.
Side effects often can be controlled with medications or changes in your diet. Tell your doctor or nurse if you experience any of them, so they can work to help you feel better.
Caring for Yourself During Treatment
- Getting plenty of rest during treatment.
- Follow your doctor’s orders, but don’t be afraid to ask for help. Ask if you are unsure about anything.
- Tell your doctor about any medications or vitamins you are taking to make sure they are safe to use during radiation therapy.
- Eat a balanced diet. If food tastes funny or if you are having trouble eating, tell your doctor, nurse or dietician. They may be able to help you change the way you eat.
- Treat the skin that is exposed to radiation with care. Clean the area with warm water and mild soap only, and use lotions or ointments only after checking with your doctor or nurse. Keep this area out of the sun and avoid applying hot or cold packs.
- Living with cancer is tough. Seek out help and support from family and friends. Your radiation oncology nurse can also recommend support groups that meet in person or correspond on the Internet