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. 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.
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. Do
Hemorrhoids Lead to Colon Cancer?
No,
but hemorrhoids may produce symptoms
similar to colon polyps or cancer,
such as bleeding or a change in bowel
habits, if these abnormalities should
persist you should contact your
doctor. 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.
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. 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, between the colon and the
anus. Colon
Cancer
The
main treatment of the cancer is surgery.
The purpose of surgery is threefold:
1) During the operation the abdominal
cavity is explored for signs of cancer
outside the bowel; 2) the bowel containing
the tumor is removed, and the bowel is
reconnected; 3) 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. 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
than 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 discovered at an early age.
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.
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. 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. 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.
Related
Topics
What
Is a Flexible Sigmoidoscopy?
What
Is a Colonoscopy?
Hereditary
Factors |
