RADIATION
THERAPY for COLORECTAL CANCER
Facts to Help People Understand
Treatment
 About
Colorectal Cancer Colorectal cancer includes malignant or cancerous
tumors of the colon and/or the rectum. -
The
colon extends from the end of the small intestine to the rectum. It consists of
ascending, transverse and descending segments. -
The
sigmoid colon is roughly S-shaped and is the lower portion of the descending colon,
leading into the rectum. -
The rectum
is part of the digestive system. It makes up the final five inches of the colon. -
Colorectal cancer can affect any of these areas.
Facts About Colorectal Cancer General
Risk Factors for Colorectal Cancer The majority of colorectal
tumors are found in patients over age 50. However, the disease can happen at any
age so it is important to know your family history and the following risk factors. Screening for Colorectal
Cancer The American Cancer Society recommends that, beginning
at age 50, both men and women be screened for colorectal cancer according to one
of the following schedules (see Diagnosing Colorectal Cancer section inside for
definitions of these tests): -
Yearly fecal
occult blood test. -
Sigmoidoscopy every five years. -
Double-contrast barium enema every five years. -
Colonoscopy every 10 years.
People who have any of the colorectal cancer risk factors should consult with
their doctor about earlier, more frequent screening. Signs of Colorectal
Cancer Often there are no obvious signs of colorectal cancer,
but some symptoms can include: -
Change in
bowel frequency, such as alternating episodes of diarrhea and constipation. -
Bloody bowel movements or rectal bleeding. -
General abdominal discomfort. -
Unexplained weight
loss. -
Chronic fatigue. -
Bloating. -
Unexplained anemia.
Diagnosing Colorectal Cancer Special tests to evaluate
the colon and rectum are used to detect and diagnose colorectal cancer.
-
A physical exam to assess your overall health, including
a digital rectal exam (DRE) to evaluate the rectum for abnormal masses. -
Fecal occult blood test where your stool will be checked for
blood. -
A sigmoidoscopy to look inside the rectum
and sigmoid colon for polyps or other abnormal areas that may be cancerous using
a thin, lighted tube. -
During a double-contrast
barium enema, your colon is filled with a fluid containing barium. The barium
is then drained out and air is put into the intestine. X-rays of the area are
then taken to look for abnormalities. -
A colonoscopy
uses a longer lighted tube to look inside the rectum and the entire colon for
polyps or other abnormal areas that may be cancerous.
To determine for sure if you have cancer, some tissue will be removed during
sigmoidoscopy or colonoscopy and examined under a microscope. This test is called
a biopsy. Your doctor may also request a CT or PET scan to see if other body parts
are involved. Treating Colorectal Cancer The primary
treatment for cancers of the colon and rectum is surgery. For cancers that have
not spread, surgery alone may cure your
cancer. -
Depending on the location and stage of your cancer, your doctor may recommend
chemotherapy and/or radiation therapy either before or after surgery. -
For rectal cancer, radiation is usually given with chemotherapy.
It can be given before surgery (called preoperative or neoadjuvant therapy) or
after surgery (called postoperative or adjuvant therapy). Depending on the location
and stage of your tumor, preoperative therapy may allow the surgeon to spare your
anal sphincter. This would avoid the need for a permanent colostomy and may reduce
the chance of the cancer coming back. Understanding
Radiation Therapy Radiation therapy, sometimes called radiotherapy,
is the careful use of radiation to safely and effectively treat cancer.
-
Cancer doctors called radiation oncologists use radiation
therapy to try to cure cancer, to control cancer growth or to 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 are able to repair themselves in a way
cancer cells cannot. After a diagnosis of
colorectal cancer has been established, it's important to talk about your treatment
options with a radiation oncologist. External Beam Radiation Therapy
External beam radiation therapy involves a series of daily outpatient treatments
to accurately deliver radiation to the area at risk. -
Before beginning treatment, you will be scheduled for a simulation to map out
the area being treated. This will involve having X-rays and/or a CT scan. You
will also receive tiny tattoo marks on your skin to help the therapists precisely
position you for daily treatment. -
Treatment
is given once a day, Monday through Friday, for about six weeks. -
Newer technologies like 3-dimensional conformal radiotherapy
(3D-CRT) and intensity modulated radiation therapy (IMRT) are being evaluated
for use in treating colorectal cancer. Ask your radiation oncologist for more
information on these treatments. Possible
Side Effects People with colorectal cancer often get chemotherapy
while they are receiving radiation. Side effects during treatment result from
both the local effects of radiation to the pelvic area and the systemic effects
of chemotherapy throughout the body. -
Possible
side effects from radiation include more frequent bowel movements, diarrhea, abdominal
cramping, pressure or discomfort in the rectal area, urinating more often, burning
with urination, skin irritation, nausea and fatigue. These are usually temporary
and resolve after your treatment ends. -
Chemotherapy
side effects will depend on the specific drug you receive. -
Side effects are not the same for all patients. Ask your doctor what you can expect
from your specific treatment. -
Many of these
side effects can be well controlled with medications and changes to your diet.
Tell your doctor or nurse if you experience any discomfort so it can be treated.
About ASTRO The American Society for Therapeutic Radiology
and Oncology is the largest radiation oncology society in the world. The Society's
mission is to advance the practice of radiation oncology by promoting excellence
in patient care, promoting research and disseminating research results. Learning
About Clinical Trials The radiation oncology team is constantly
exploring new ways to treat colorectal cancer through studies called clinical
trials. Today's standard radiation therapy treatments are constantly being refined
due to the results of trials. For more information, please contact the following
organizations: National Cancer Institute
www.cancer.gov/clinicaltrials Radiation
Therapy Oncology Group
www.rtog.org About
the Radiation Oncology Team Radiation oncologists are the doctors
who oversee the care of each patient undergoing radiation treatment. Other members
of the radiation oncology team include radiation therapists, radiation oncology
nurses, medical physicists, dosimetrists, social workers and nutritionists. To
locate a radiation oncologist in your area, visit www.astro.org/patient. Helpful
Web Sites On Colorectal Cancer :: American Cancer Society
www.cancer.org Colon
Cancer Alliance
www.ccalliance.org Colorectal
Cancer Network
www.colorectal-cancer.net Cancer
Research and Prevention Foundation
www.preventcancer.org National
Colorectal Cancer Research Alliance
www.nccra.org
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