Colorectal Cancer Health Center

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

A risk factor is anything that increases your chance of getting a disease such as cancer. Risk factors for getting colorectal cancer include:

Your age

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 50.

Your family's medical history

You 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 are true:

• You have at least three relatives who have had colon cancer, and at least one of them is a parent, brother, or sister.
• 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 carefully watched. Genetic testing can tell you whether you carry a changed, or mutated, gene that can cause FAP or HNPCC.

Most people who get colorectal cancer do not have a personal or family history of the disease.

Your medical history

Your chances of getting colorectal cancer are higher if you have had:

• Colorectal cancer in the past.
• Another type of cancer, such as cancer of the ovary or cancer of the endometrium.
• Polyps removed from your colon, especially if you had large polyps or a large number of polyps.
• Ulcerative colitis or Crohn's disease for more than 10 years.
• Radiation therapy in your abdomen or pelvis.

Lifestyle changes to reduce your risk

• Quit smoking, if you smoke.
• Keep a healthy body mass index (BMI).
• Be physically active with regular exercise.
• Eat more whole grains, fruits, vegetables, poultry, and fish.
• Drink less than 2 alcohol drinks a day.¹