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Colorectal Cancer
Colorectal cancer is the second most common cancer in the United States,
striking 140,000 people annually and causing 60,000 deaths. That is a
staggering figure considering the disease is potentially curable if it
is diagnosed in the early stages.
Who is at Risk?
Though colorectal cancer may occur at any age, more than 90% of the patients
are over the age of 40, at which point the risk doubles every ten years.
In addition to age, other high risk factors include a family history of
colorectal cancer or polyps and a personal history of ulcerative colitis,
colon polyps, or cancer of other organs, especially of the breast or uterus.
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What are the Symptoms?
The most common symptoms are rectal bleeding and changes in bowel habits,
such as constipation or diarrhea. These symptoms are also common in other
diseases so it is important you receive a thorough examination should
you experience them. Abdominal pain and weight loss are usually late symptoms
possibly indicating more extensive disease.
Unfortunately, many polyps and early cancers fail to produce symptoms.
They often do not bleed or cause a change in bowel habits, and they do
not hurt. Therefore, it is important that your routine physical examination
include colorectal cancer detection procedures.
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How Does it Start?
Nearly all colorectal cancer begins in benign polyps. These are small
growths that occur on the bowel wall and may eventually increase in size
and become cancerous. Colon polyps are very common, but few become cancerous.
However, at this time it is not possible to identify which ones will become
cancerous. Therefore, it is generally recommended that the polyps be removed
to prevent the development of cancer.
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Do Hemorrhoids Lead to Colon Cancer?
No, but hemorrhoids may produce symptoms similar to colon polyps or cancer.
Should you experience bleeding or a change in bowel habits, you should
be examined and evaluated by a doctor.
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Can Colorectal Cancer be Prevented?
There are steps that reduce the risk of developing colorectal cancer.
Regular screening examinations and removal of any polyps have been shown
to reduce the risk of colon cancer. Once you reach 50 years of age, or
sooner if you have a family history of colon cancer, you should have a
flexible sigmoidoscopy (the inspection of the lower bowel with a lighted
instrument about the width of a finger). If polyps are found, it is recommended
that they be removed by an outpatient procedure called colonoscopy. In
addition to removing the polyps, the entire colon will be examined. These
examinations produce minimal cramping lasting a few minutes. Fear of cancer
or the possible treatment should not prevent you from having a screening
examination.
Though not definitely proven, there is some evidence that diet may play
a significant role in preventing colorectal cancer. Much research is being
done about the relationship of diet to colon cancer. At the present time
a low fat and high fiber diet is recommended. Eating more cruciferous
vegetables, such as broccoli and cauliflower, may add additional protection.
There is some evidence to suggest that taking aspirin on a regular basis
protects against colon cancer. Other preventative medications are currently
being investigated. It is important that you check with your doctor before
beginning any medication.
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What Tests are Done before Treatment?
Treatment of colorectal cancer depends on the location and extent of
the tumor. Before any treatment is started, tests are done to check the
colon and rectum for other cancers or polyps. This can be done through
colonoscopy (looking inside the colon with a lighted flexible tube) or
a barium enema x-ray of the colon. Other tests that might be used include
blood tests, a chest x-ray, or scans of the abdomen to determine if the
disease has spread. For cancers in the rectum, an ultrasound probe can
be inserted into the rectum to provide a picture of how far into the bowel
wall the tumor has grown and whether it involves any nearby lymph glands.
Once these results are available, a treatment plan is chosen.
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How is Colorectal Cancer Treated?
The large intestine is composed of the colon and rectum. The colon is
the upper portion of the large intestine. The rectum is the lower 15 centimeters
of the large intestine.
Colon Cancer
The main treatment of the cancer is surgery. The surgeon removes the
section of colon containing the tumor. The two ends of the colon are
then reconnected. The tissue next to the colon contains the lymph nodes.
These nodes are removed because the lymph system is one of the ways
cancer cells spread to other parts of the body. The pathologist carefully
examines the removed tissue to determine the extend of the cancer in
the colon wall and in the lymph nodes. If cancer is found in the lymph
nodes, chemotherapy may be recommended after surgery.
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Rectal Cancer
Cancer of the rectum behaves somewhat differently than cancer of the colon.
Also because it is located at the end of the colon if a portion is removed
there may not be enough bowel to reconnect the two ends. For these reasons
treatment of cancer of the rectum may be different that cancer of the
colon.
Treatment of rectal cancer has changed in recent years. We now know
that local treatments offer cure rates equal to major surgery if the
cancer is limited to the wall of the rectum. Local treatment options
include removal of the cancer through the rectum, destroying the cancer
with laser or cautery and endocavitary radiation ( a special type of
radiation delivered through an instrument placed into the rectum). Most
of the procedures are done as outpatient procedures. Complications are
rare and recovery is usually minimal so the procedures are well tolerated
even by older patients. There are advantages and disadvantages to each
that will be discussed by your doctor if local treatment is appropriate.
Unfortunately, many cancers are not identified until they are too
extensive for local therapy. Major abdominal surgery is still necessary
for most patients. Advances in surgical technique make it possible for
surgeons to rejoin the two sections of bowel in the majority of cases.
A stoma (bringing the end of the small intestine out to the skin) may
be done temporarily to allow the reconnected ends of the bowel to heal.
When the cancer is too close to the end of the rectum, there is not
enough tissue to rejoin the ends. Therefore, the surgeon must remove
the entire rectum and anus and use the end of the colon to construct
a colostomy. A colostomy is made by bringing the end of the colon through
a hole in the abdominal wall and sewing it to the skin edges. An appliance
or bag is worn over the colostomy to collect the stool and gas that
is eliminated. Modern appliances, improved surgical technique and patient
education help people maintain their colostomy easily and discreetly
and to lead normal lives.
In some instances, radiation and chemotherapy may be recommended to
shrink the tumor before surgery. This makes removal of the cancer easier
during surgery.
Sometimes the cancer will be found to have already metastasized (spread
to other organs) when it is first diagnosed. In such cases, an individual
treatment plan is made after extensive testing. Surgery, radiation and
chemotherapy may all be used where appropriate.
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Prognosis
Survival after colorectal cancer is related to the extent of the disease
when it is first found. Early detection means that minimal treatments
may be possible and that the survival rate is better. If found in an early
stage, there is a 90% survival rate. If the cancer is more extensive,
survival rates fall to approximately 50%. Some people delay investigating
a new symptom or postpone routine screening exams out of fear of cancer
and the treatment that may be required.
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Follow-Up Care
A person with a history of colorectal cancer is at risk for recurrence
of the cancer and for the development of new polyps or cancers in the
remaining colon. For these reasons follow-up examinations are important.
Colonoscopy is done to identify new growths early so that they can be
removed without surgery. These examinations are generally necessary every
3-5 years unless an individual is forming many polyps. Other tests may
be done to detect recurrence. The exact tests depend upon the location
of the original cancer, the person's general health, and the treatment
plan used. Your doctor will discuss the exact follow-up with you.
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Summary
Colorectal cancer is unfortunately a common disease in this country.
Fortunately, it can be prevented or detected early by routine screening
exams. If detected early, the treatment is straightforward and the survival
rate is good.
Colon and rectal surgeons are experts in the surgical and non-surgical
treatment of colon and rectal problems. They have completed advanced training
in the treatment of colon and rectal problems in addition to full training
in general surgery.
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