NCCN Guidelines for Patients™: Colon Cancer
2.3 Am I at risk?
Doctors haven’t found the causes of colon cancer. However, some risk factors are
known. Risk factors can be activities that people do, things in the environment, or
biological features that are passed down from parents to children through genes.
If one or more risk factors apply to you, it doesn’t mean you’ll get colon cancer.
Likewise, colon cancer occurs in some people who have no known risk factors.
The major risk factors of colon cancer are as follows:
Your risk for colon cancer increases as you age. In fact, 90 out of 100 people with
colon cancer are diagnosed at age 50 or older. The average age of all people
diagnosed with colon cancer is 72 years of age.
Not all polyps are the same. They all grow from the mucosa, but they differ in size,
shape, and how their cells look. The odds of cancer forming in polyps differs by the
type of polyp. The three types of colon polyps are:
have cells that grow fast. They are often found in the last
part of the colon. They rarely become cancerous.
• Adenomatous polyps
, or adenomas, have cells that don’t look like normal colon
cells. They are the most common type of polyp. Most do not become cancerous,
but most polyps with cancer started as adenomas. Your risk for cancer forming
in adenomas is high if 3 or more adenomas are found, the adenomas are
bigger than the width of an AAA battery, and the adenomas have a ruffled
structure like a cauliflower. Adenomas with a ruffled structured are called
• Inflammatory polyps
often grow after a flare-up of an inflammatory bowel
disease. They can have any shape. The chance of them becoming cancerous
Part 2: About colon cancer
in cells that line organs and
make fluids or hormones
Instructions in cells
for building new cells and
controlling cell behavior
The growth of
cancer beyond local tissue
that increases the chance of
getting a disease
A tissue mass made
from an abnormal growth