Colon Cancer

What is a risk factor?

A risk factor is anything that may increase your chance of having a disease. Risk factors for a certain type of cancer might include smoking, diet, family history, or many other things. The exact cause of someone’s cancer may not be known. But risk factors can make it more likely for a person to have cancer.

Things you should know about risk factors for cancer:

• Risk factors can increase a person's risk, but they do not necessarily cause the disease.
• Some people with risk factors never develop cancer. Other people can develop cancer and have few or no risk factors.
• Some risk factors are very well known. But there is ongoing research about risk factors for many types of cancer.

Some risk factors like family history may not be in your control. But others may be things you can change. Knowing the risk factors can help you make choices that might lower your risk. For example, if an unhealthy diet is a risk factor, you may choose to eat healthy foods. If excess weight is a risk factor, you may decide to try to lose weight.

Who is at risk for colorectal cancer?

Anyone can get colorectal cancer. But there are some factors that can increase your risk for colorectal cancer, such as:

• Age. Most people who have colorectal cancer are over age 50. But it can occur at any age.
• Race and ethnicity. African-Americans have the highest risk for colorectal cancer of all racial groups in the U.S. And Jews whose families are from Eastern Europe (Ashkenazi Jews) have one of the highest colorectal cancer risks of any ethnic group in the world.
• Gender. Men have a slightly higher risk of this disease than women.
• Personal history of colorectal polyps. Polyps are growths that can occur in your colon and rectum. They are common in adults over age 50. Often they're benign, or not cancer. But some polyps can become cancer over time. If you have had polyps in the past, you may be more likely to get colorectal cancer.
• Personal history of colorectal cancer. People who have had colorectal cancer have an increased risk of getting it again.
• Ulcerative colitis or Crohn's disease. People who have an inflamed lining of the colon caused by one of these conditions have a greater risk for colorectal cancer.
• Family history. People are at higher risk if they have a family history of colorectal cancer or polyps in a first-degree relative, such as a parent, sibling, or child. The risk is greater if the relative was diagnosed before age 45. The risk is also greater if more than 1 relative was diagnosed. Still, most people who get colorectal cancer don’t have a family history of the disease.
• Certain inherited syndromes. People with certain syndromes have a very high risk of colorectal disease. These include familial adenomatous polyposis (FAP) and Lynch syndrome, also known as hereditary nonpolyposis colon cancer or HNPCC.
• Obesity. Colorectal cancer is more common in people who are very overweight than people who are not. This is especially true for men. 
• Not being active. People who are not active are at increased risk of the disease.
• Diet. Colorectal cancer is often linked to a diet high in red meats, such as beef, pork, lamb, and veal. It is also linked to a diet high in processed meats, such as hot dogs and lunch meats.
• Type 2 diabetes. People with type 2 diabetes are more likely to get colorectal cancer. Type 2 diabetes and colorectal cancer share some of the same risk factors, such as obesity and not being active. But even after taking these factors into account, people with type 2 diabetes still have a higher risk for colorectal cancer.
• Smoking. Smoking raises a person's risk for colorectal cancer.