Colorectal Cancer Causes and Risk Factors

There are several known risk factors for colorectal cancers. Colorectal cancers usually start as a growth on the lining of the colon or rectum. These growths are called polyps. Polyps in the colon are common and most are not cancerous, however some can become cancerous over time.

Risk factors for colorectal cancer

Some factors may make you more likely to develop colon cancer or rectal cancer:

• Diet: Eating a lot of red meat, processed meats or meat cooked at high temperature raises your risk. Diets low in fiber may also increase your risk.
• Physical activity: Not getting enough exercise and having a sedentary lifestyle puts you at risk.
• Tobacco use: Your risk is higher if you smoke or use other products that contain tobacco.
• Alcohol use: Heavy drinking raises your risk.
• High body weight: Having a BMI over 24 and/or diabetes increase your risk.
• Age: Risk increases after age 50, though the incidence of colorectal cancer is rapidly rising in younger adults.
• Race: Risk is higher for Black people.
• Family history: If you have one or more close relatives with colorectal cancer or polyps, your risk may be higher. Your risk is higher when more than one relative has had colon or rectal cancer or if a family member had colorectal cancer before age 45.
• Personal history: If you’ve had colorectal cancer or polyps, you’re at higher risk of having them again. Having a polyp bigger than one centimeter, more than three polyps or abnormal cells in a polyp increases your risk. A history of ovarian cancer also increases your risk.
• Inflammatory bowel disease: Conditions like Crohn’s disease or ulcerative colitis increase your risk if you’ve had them for eight years or longer.
• Gender: Both men and women can develop colorectal cancer. The risk for men is slightly higher.
• Genetic factors: Your risk is higher if you have inherited gene mutations and genetic conditions like Lynch syndrome, familial adenomatous polyposis or rare conditions like Peutz-Jeghers syndrome (PJS), MUTYH-associated polyposis (MAP) or cystic fibrosis (CF).

Understanding these risk factors can help you prevent colorectal cancer and detect it earlier.

Preventing colorectal cancer

While you can’t guarantee you won’t get colon cancer or rectal cancer, you can take these steps to lower your risk:

• Eat plenty of high-fiber foods like fruits, vegetables and whole grains. They have fiber, minerals and vitamins that may help prevent cancer. Limit red meat and avoid processed meats.
• Aim for at least 150 minutes of moderate physical activity or 75 minutes of vigorous activity each week. If you’re inactive, start with a few minutes and build up gradually. Talk to your health care provider before you start a new exercise program.
• Maintain a healthy body weight.
• If you smoke, try to quit. Avoiding tobacco can reduce your risk of many cancers, including colon and rectal cancers.
• No alcohol is best for cancer prevention. If you choose to drink, have no more than one drink a day if you’re a woman and two drinks a day if you’re a man.
• Get regular colorectal cancer screenings like colonoscopies starting at age 45, or earlier if you’re at higher risk. Screenings can help detect cancer early when it’s easier and more successful to treat.
• Talk to your doctor about your risk factors and any symptoms you have. Regular check-ups can help catch issues early.

Learn about signs, symptoms and screening for colon cancer and rectal cancer.

If you’re concerned about your risk factors for colorectal cancer, consider making an appointment with one of our specialists. The earlier you start prevention, the better chance you have of not developing cancer.

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