RADIATION THERAPY FOR COLORECTAL CANCER
Facts to Help People Understand Treatment

Diagnosing Colorectal Cancer

Doctors use special tests to evaluate the colon and rectum and to detect and diagnose colorectal cancer.

• A physical exam to assess the patient’s overall health, including a digital rectal exam (DRE) to evaluate the rectum for abnormal masses.
• Fecal occult blood test that checks the stool for blood.
• A sigmoidoscopy that uses a thin, lighted tube to look inside the rectum and sigmoid colon for polyps or other abnormal areas that may be cancerous.
• During a double-contrast barium enema, the colon is filled with a fluid containing barium. The barium is then drained out and air is inserted into the intestine. Then X-rays are taken of the area to look for abnormalities.
• A colonoscopy uses a longer lighted tube to search the rectum and the entire colon for polyps or other abnormal, possibly cancerous areas.

To determine for sure if you have cancer, your doctor will perform a biopsy, during which some tissue will be removed during sigmoidoscopy or colonoscopy and examined under a microscope. Your physician may also request a CT or PET scan to see if the cancer has spread.

Treating Colorectal Cancer

The most common treatment for cancers of the colon and rectum is surgery. For cancers that have not spread, surgery alone may cure the cancer.

• Your physician may recommend chemotherapy and/or radiation therapy either before or after surgery depending on the location and stage of your cancer.
• Rectal cancer is usually treated with both radiation and chemotherapy. Treatment can be given before surgery (preoperative or neoadjuvant therapy) or after surgery (postoperative or adjuvant therapy). Depending on the location and stage of the tumor, preoperative therapy may allow the surgeon to spare the anal sphincter. This would avoid needing to have a permanent colostomy and may reduce the chance of a recurrence of the cancer.

Understanding Radiation Therapy

Radiation therapy, sometimes called radiotherapy, is the careful use of radiation to safely and effectively treat cancer.

• Radiation oncologists use radiation therapy to try to cure cancer, to control cancer growth or to relieve pain or other symptoms.
• Radiation therapy damages tumor cells’ ability to multiply. The body naturally eliminates these cells after they die.
• Radiation may not affect the healthy cells near the tumor, but if they are affected, they can repair themselves in a way tumor cells cannot.

After a diagnosis of colorectal cancer has been established, discuss treatment options with a radiation oncologist.

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