Cancer: One of the Most Common Forms of Cancer
Colon cancer is one of the most
common forms of cancer in the U.S., affecting about 130,000 Americans
each year, according to the National Cancer Institute. Colon cancer
is more common than rectal cancer, and more dangerous: About half
of colon cancer patients eventually die from the disease because
it often isn't detected until the later stages. Due to increased
testing, death rates from colorectal cancer have dropped by 25 percent
in women and 13 percent in men over the past 20 years. Fortunately,
colon cancer is also one of the most curable forms of cancer. When
detected early, more than 90 percent of patients can be cured.
What is colon cancer?
As the name suggests, colorectal cancer is cancer of the colon or
rectum, which together form the 6-foot-long tube in the digestive
tract called the large intestine. This disease begins as a polyp
- or fleshy tumor, shaped like a mushroom or a dome-like button
- on the inside lining of the colon. Colon polyps start out as benign
tumors but in time may become malignant. The larger the polyp, the
more likely it is to contain cancer cells. Although they're very
common among older people, it is not clear what causes polyps in
There now is strong medical evidence that there are abnormal genes
for colon polyps and cancer that can be passed from parent to child.
The genes within each cell are the hereditary structures that tell
the cell what it should do. When these controlling genes are absent
there is a tendency to grow polyps. The cells in the polyp eventually
become uncontrolled and turn into a cancer. Colon cancer also can
develop with other conditions, such as ulcerative colitis, a chronic
inflammation in the colon.
Who is at risk for developing colon cancer?
Cancer of the colon is most common after age 50, but on rare occasions,
the disease strikes younger people. For unknown reasons, the tumors
that develop in young people are often especially fast-growing and
likely to spread. Relatives of a person who has had colon cancer
at a young age are at a slightly increased risk.
Certain genes also increase the risk of developing numerous polyps
in the colon and increase the risk of developing colon cancer at
a younger age. Inherited types of colon cancer also exist. Family
members of people who develop numerous polyps or colon cancer at
an early age can have genetic testing performed.