What is the colon and how does it work?
The colon is the large intestine; it is the lower part of your
digestive tract. The intestine is a long, tubular organ consisting
of the small intestine, the colon (large intestine) and the
rectum, which is the last part of the colon. After food is swallowed,
it begins to be digested in the stomach and then empties into
the small intestine, where the nutritional part of the food
is absorbed. The remaining waste moves through the colon to
the rectum and is expelled from the body. The colon measures
about 5 feet long and 2.5 inches in diameter. The lumen (interior)
of the colon has a delicate lining. In addition to lubricating
the passage of waste through the colon, this moist lining protects
underlying tissues and the nerve endings that extend down into
the colon wall. The colon and rectum absorb water and hold the
waste until you are ready to expel it.
What is colon cancer?
A cancer is a group of cells (usually derived from
a single cell) that has lost its normal control mechanisms
and thus has unregulated growth. Cancerous (malignant) cells
can develop from any tissue within any organ. As cancerous
cells grow and multiply, they form a mass of cancerous tissue—called
a tumor—that invades and destroys normal adjacent tissues.
The term "tumor" refers to an abnormal growth or
mass; tumors can be cancerous or non cancerous. Cancerous cells
from the primary (initial) site can spread (metastasize) throughout
the body. Colon cancer develops in the colon and/or small
bowel. In most cases, colon cancer begins as a benign, or
non-cancerous, polyp on the bowel wall and eventually increases
in size and becomes cancerous. Unfortunately, many polyps
and early cancers fail to produce symptoms. The key to survival
is early detection of this type of cancer because it is curable
in its early stages. If everyone aged 50 and older had regular
colorectal cancer screening tests, more than one-third of
deaths from this cancer could be avoided. When diagnosed and
treated in the early stages, between 80 - 90 percent of colon
cancer patients return to their normal health.
Staging of Colon Cancer
| Stage 0: |
Cancer has not grown beyond the inner lining
of your colon.
Treatment: Removal
of the tumor through the colonoscope or surgical resection
of the colon. |
| Stage I: |
Cancer has grown through several layers of the colon.
Treatment: Surgical resection of the
colon. |
| Stage II: |
Cancer has grown into the wall of the colon and may
have extended into nearby tissue. Treatment:
Surgical resection of the colon and potential radiation
therapy. |
| Stage III: |
Cancer has spread to nearby lymph nodes, but not other
parts of the body.
Treatment: Surgical
resection of the colon, chemotherapy, and potential radiation
therapy. |
| Stage IV: |
Cancer has spread to distant organs and tissues.
Treatment: Surgical resection of the
colon, chemotherapy, and potential radiation therapy. |
| Recurrent: |
Cancer has returned after treatment.
Treatment:
Chemotherapy and potential surgical resection of the colon. |
Colon Cancer Facts and Stats
- Both men and women are at risk.
- Overall, colon cancers are the third most common cancers
in men and women,
and the second leading cause of cancer death in the United
States.
- Ninety-three percent of cases occur in people aged 50
and older. The risk of developing it increases with age.
- Colon cancer is the third most common cancer in both
African American men and
women in the United States.
- Colon cancer is the second most commonly diagnosed cancer
in both Hispanic
and Latino men and women.
- In 2004, an estimated 146,940 new cases will be diagnosed
in the United States.
Of these new cancer cases, 106,370 will be colon cancer
and 40,570 will be rectal
cancer. This means someone will be diagnosed every four
minutes.
- An estimated 56,730 deaths are expected to occur in 2004,
accounting for
approximately 10 percent of cancer deaths this year in the
United States.
- African Americans have the highest death rate from colon
cancer of any racial or
ethnic group in the United States.
- Colon cancer is the second leading cause of cancer deaths
among African
American men and women combined
- Colon cancer is the second leading cause of cancer death
among Hispanic and
Latino men and women combined.
- One out of 18 people in the United States will develop
colon
cancer in their lifetime.
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