Colorectal Cancer: Risk Factors
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, such as 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, your healthcare provider may check your weight or help you lose weight.
Who is at risk for colorectal cancer?
Anyone can get colorectal cancer. But there are some factors that can increase your risk, such as:
- Age. Most people who have this cancer are over age 50. But it can occur at any age.
- Race and ethnicity. African-Americans have the highest risk for colorectal cancer in the U.S. And Jews whose families are from Eastern Europe (Ashkenazi Jews) have 1 of the highest colorectal cancer risks of any ethnic group in the world.
- Sex. Men have a slightly higher risk of this disease than women.
- 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 called adenomas in the past, you may be more likely to get colorectal cancer.
- 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 1 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. This may be 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. But 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. This includes familial adenomatous polyposis (FAP). And it includes Lynch syndrome. This is also known as hereditary nonpolyposis colon cancer (HNPCC).
- Obesity. Colorectal cancer is more common in people who are very overweight than people who are not. This is more 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. This includes beef, pork, lamb, and veal. It is also linked to a diet high in processed meats. These include hot dogs and lunch meats.
- Drinking a lot of alcohol. People who drink a lot of alcohol are more likely to get colorectal cancer.
- Type 2 diabetes. People with type 2 diabetes are more likely to get colorectal cancer.
- Smoking. Smoking raises a person's risk for this cancer.
What are your risk factors?
Talk with your healthcare provider about your risk factors for colorectal cancer and what you can do about them. Some risk factors, such as your age and family history, are not under your control. But there are things you can do that might lower your risk of colorectal cancer. These include being active, staying at a healthy weight, eating a healthy diet, limiting alcohol, and not smoking. Getting the recommended screening tests for colorectal cancer is also very important, especially if you have risk factors. Screening can often find cancer early, when it is likely to be easier to treat. Screening can even help prevent some cancers by finding and removing colorectal polyps before they turn into cancer.