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What is Colorectal Cancer?
Colorectal cancer occurs in the colon or rectum, which are a part of the
large intestine. Caused by the growth of malignant cells in the colon or
rectum, colorectal cancer is believed to form from non-cancerous growths,
called polyps, on the walls of the colon or rectum. As time passes, polyps
may begin to grow abnormally and become cancerous.
The American Cancer Society and the American Gastroenterological Association
state the following facts:
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Colorectal cancer is the third most common cancer diagnosed in men
and in women in the United States
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Colorectal cancer is the second-leading cause of cancer-related
deaths in the United States
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80 to 90 million Americans face a higher risk of developing
colorectal cancer because of age, heredity and lifestyle factors
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Due to increased screening, earlier detection, and treatment
advances, a nationwide decline in death rates from colorectal cancer has
been seen over the last 15 years
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Today, 1 million American women and men have survived colorectal
cancer
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Risk Factors
Certain lifestyle factors may contribute to the increase in risk of
developing colorectal cancer such as:
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A diet that is high in red, processed, or heavily cooked meat
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Sedentary lifestyle
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Obesity (particularly having excess fat in the waist area rather
than the hips or thighs.)
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Cigarette smoking (studies show that smokers are 30 to 40 percent
more likely than nonsmokers to die of colorectal cancer because they are
more likely to develop polyps.)
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Diabetes (studies indicate that those that are living with diabetes
are at an increased risk of developing colorectal cancer by
approximately 30 to 40 percent
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Personal and family history (People who have had colorectal cancer,
ovarian, uterine, or breast cancers, have a slightly increased risk for
colorectal cancer. If parents or siblings have had colorectal cancer, a
risk of developing colorectal cancer increases.)
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Digestive diseases -- People who have had disorders that cause long-term
inflammation of the colon wall (such as ulcerative colitis and Crohn's
disease) are more susceptible to colorectal cancer.
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Common Symptoms
Colorectal cancer may arise without any symptoms. Screening tests are
therefore strongly recommended (such as a colonoscopy and a test for blood
in the stool) to detect the cancer at its earliest stage, when the cancer is
more curable. It is advised that a doctor should be seen immediately if one
of the following warning signs occurs:
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Rectal bleeding or blood in the stool
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Recurring stomach pain or cramping
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Unexplainable changes in bowel habits, such as narrow, ribbon-like
stools
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Discomfort during bowel movements or constantly feeling like you
need to have a bowel movement
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Loss of appetite, mysterious weight loss
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Screening and Diagnosis
Early detection is essential to successful treatment and recovery.
Therefore, routine screening is strongly suggested A physical examination
and medical testing are required to find the cause of symptoms. Colorectal
cancer screening involves a few steps. A doctor will review personal medical
history, family history, and potential symptoms. Following the review, one
or more of the following medical tests will be given:
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Digital rectal examination (DRE)- By inserting a gloved,
lubricated finger into the rectum, doctors can feel for lumps or unusual
masses in the rectum
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Fecal occult blood test- A test kit completed in the privacy
of the patient's home and returned to the doctor's office for evaluation
of hidden blood in the stool
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Sigmoidoscopy- An outpatient procedure using a long,
flexible, lighted tube to check the rectum and lower part of the colon
for polyps and cancerous tumors
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Colonoscopy- An outpatient procedure using a colonoscope,
which is a long, flexible, lighted tube (much longer than a
sigmoidoscope), that allows the doctor to view the entire colon and
rectum
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Barium enema (lower GI series)- A liquid containing barium is
put into the rectum and a series of x-rays are taken of the lower
gastrointestinal tract
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Stages of Colorectal Cancer
If a diagnosis is made, additional examinations may be performed to
determine its magnitude. This process is called staging. Knowing how far the
cancer has progressed is vital when deciding what regimen of treatment might
be most appropriate for the patient.
As colorectal cancer progresses from Stage 0 to Stage IV, tumors grow
through the lining of the rectum or colon and spread to lymph nodes and
other organs.
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Stage 0 (carcinoma in situ): Cancer is found in the innermost lining
of only the rectum or colon
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Stage I: Cancer has spread beyond the innermost wall of the rectum
or colon to the middle layers
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Stage II: Cancer is found in the middle layers or outside of the
colon or rectum, but not in the lymph nodes
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Stage III: Cancer has invaded nearby lymph nodes, but not other
parts of the body
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Stage IV: Other parts of the body, such as the lungs or liver, are
affected by the cancer
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Common Treatment Options
The choice of treatment for colorectal cancer depends on the stage of the
disease. Doctors will determine how large the tumor has grown, how deeply it
has penetrated the layers of the colon or rectum, and whether it has spread
to other organs (most commonly the liver), lymph nodes, or other parts of
the body. The goal of treatment is to preserve healthy tissue while killing
tumors at their original point, as well as any cancer cells that have spread
throughout the body. The following are examples of several treatment
options:
Surgery
The most common type of treatment for colorectal cancer is surgery. During
this procedure, doctors often use colonoscopy to remove small tumors and
cancerous polyps in the colon or upper rectum. For tumors that are larger in
size, surgical oncologists remove cancerous cells and some of the nearby
healthy tissue through an opening in the abdomen. Adjacent lymph nodes also
may be removed.
Chemotherapy
Chemotherapy treatment uses drugs to stop the growth of cancer cells, either
by destroying the cells or by stopping the cells from dividing. Whether the
chemotherapy is given as the primary treatment or as an adjuvant
(additional) treatment to surgery, depends on the type and stage of cancer.
Chemotherapy drugs can be taken orally or by injection. The patient's doctor
will prescribe a specific drug protocol that will suit the type and stage of
his/her particular cancer. Discussing treatment protocols with the treatment
team is advisable in order to be aware of any possible side effects.
Radiation
When colon cancer has attached to an internal organ or the lining of the
abdomen and the surgeon cannot be certain that all the cancer has been
removed, radiation therapy is normally used. Radiation therapy is usually
performed to treat rectal cancer in order to prevent the cancer from coming
back in the pelvis where the tumor started.
Radiation therapy is a non-surgical method of treatment of cancer and other
diseases, using beams of high-energy waves called x-rays or gamma rays.
Radiation cripples or destroys tumor cells by incapacitating their genetic
material, making it impossible for these cells to continue to grow. There
are two types of radiation therapy:
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External-beam radiation therapy - Specialized medical
equipment is used to deliver radiation to the tumor site from outside
the body.
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Internal radiation therapy (also called Brachytherapy) -
Radioactive material is placed in the body near the cancer cells (also
called implant radiation or brachytherapy)
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The way the radiation therapy is performed depends on the type and stage of
the cancer being treated.
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