Colorectal cancer occurrence rates are highest among African Americans. Rates are slightly lower among whites and lowest for Asians, Pacific Islanders, American Indians, Alaskan Natives, and Hispanics.1
factor is anything that increases your chance of getting a disease such as
cancer. Risk factors for getting colorectal cancer include:
Everyone who is older than 50 has a risk
of getting colorectal cancer. And the older you are, the greater the risk. Most
cases of colorectal cancer are diagnosed in people older than 50. Most people
who get colorectal cancer have no other risk factors besides being older than
Your family's medical history
are more likely to get colorectal cancer if one of your parents, brothers,
sisters, or children has had the disease. This is considered a strong family history. Your risk depends on how old your
family member was when he or she was diagnosed and on how many members of your
family have had the disease.
You have a very strong family history if all of the following
- You have at least three relatives who have had
colon cancer, and at least one of them is a parent, brother, or
- Those relatives are spread over two generations in a row
(for example, a grandparent and a parent).
- One of those relatives
had cancer before age 50.
If you have a very strong family history of colorectal and related cancers, you may want to have genetic testing. Related cancers include ovarian cancer, stomach cancer, liver cancer, or cancer of the small bowel, among others. Genetic testing is done with a blood test that looks for changed genes (mutations).
The most common gene changes occur in two conditions:
familial adenomatous polyposis (FAP) and
Lynch syndrome, also called hereditary nonpolyposis colon cancer (HNPCC). Many
people with these changed genes will develop colorectal cancer if they are not
Genetic testing can tell you whether you carry a
changed, or mutated, gene that can cause FAP or HNPCC.
who get colorectal cancer do not have a personal or family history of the
Your medical history
chances of getting colorectal cancer are higher if you have had:
Lifestyle changes to reduce your risk