Determining Your Risk of Colorectal Cancer

Colorectal cancer is the third most common cancer in the U.S., with more than 140,000 people diagnosed each year. However, it’s also one of the most easily prevented. Many cases of colon and rectal cancer could be avoided with regular screening and certain lifestyle adjustments.

Risk factors for colorectal cancer

Some of the risk factors for colorectal cancer are biological things we can’t change, such as our age and height. But other risk factors result from our lifestyle choices, such as the amount of red meat we eat and alcohol we drink. These are areas to take action.

  • Not getting screened
  • Being older (especially age 60 or older)
  • Being tall (for women, 5’8″ or taller; for men, 5’11” or taller)
  • Having inflammatory bowel disease, such as ulcerative colitis or Crohn’s
  • Being overweight
  • Eating a diet high in red and processed meat
  • Not getting regular exercise
  • Drinking alcohol (zero is best!)
  • Smoking
  • Not getting enough calcium, vitamin D and folate

Genetic risk factors for colorectal cancer

Inherited colon cancer syndromes cause up to six percent of colorectal cancers. If you have a strong family history of colorectal cancer or cancer-related conditions, your doctor may advise you to start an alternative screening schedule. Generally, this means that you will start screening at a younger age. You may also need more frequent screening.

What does it mean to have a family history of colorectal cancer?

Having a family history of colorectal cancer means that one or more of our relatives (especially one of your parents, siblings or children) has developed the disease. If you have multiple relatives who have had colorectal cancer, or if you have relatives who were diagnosed before age 50, your doctor may recommend a more frequent screening schedule.

Colorectal cancer doesn't run in my family, but another type of cancer does. What should I do?

If colorectal cancer doesn’t seem to run in your family, but multiple family members have developed a different cancer or one family member has several types of cancer, you should still mention it to your doctor.

Genetic testing

Genetic testing for inherited cancer syndromes can help you make treatment and screening decisions under certain conditions. Washington University Physicians and genetic counselors at Siteman help identify and support patients with familial predispositions to cancers like colorectal cancer. Siteman maintains a registry of patients with known inherited tendencies for colon cancer.

What genetic syndromes are linked to colorectal cancer?

Familial adenomatous polyposis (FAP): People with FAP develop hundreds to thousands of polyps in their colons. Since any of the polyps may become cancerous, removal of the colon is recommended. Polyps may develop in other areas of the digestive system, which requires lifelong cancer screening.

Lynch syndrome: People with Lynch syndrome have an 80 percent lifetime risk of developing colorectal cancer. Women with Lynch syndrome also have a 40-60 percent lifetime risk of developing uterine cancer. Other cancers, such as gastric or kidney tumors, may be associated with this syndrome.

I have an inherited colon cancer syndrome. How does this affect my cancer screenings?

If you have an inherited colon cancer syndrome, your doctor may recommend starting colorectal cancer screening and uterine cancer screening at a younger age, and more often. Based on your family history, your doctor may recommend other screenings. Talk to your doctor about your family history and individual risk factors.

How can I lower my risk of colorectal cancer?

Anyone can take steps to lower their colorectal cancer risk. These steps include:

  • Getting regular screenings
  • Losing weight
  • Limiting red and processed meat consumption
  • Reducing alcohol intake
  • Exercising
  • Taking a daily multivitamin
  • Quitting smoking

Young adults and colorectal cancer

Many young people assume that they can’t get colorectal cancer unless they are middle-aged or older. This sometimes leads them – and even their physicians – to simply write off troublesome symptoms as digestive problems.

It’s true that older or elderly populations are more likely to get colorectal cancer. But recent research, including some done right here at Siteman, shows that increasing numbers of young people are developing colorectal cancer.

The Young-Adult Colorectal Cancer Program at Siteman focuses exclusively on the needs of colorectal cancer patients under 50.

Your Disease Risk

Physicians and researchers at Washington University and Barnes-Jewish Hospital have developed Your Disease Risk, a risk assessment tool to help you determine your risk for six chronic diseases and 12 different cancers, including colorectal cancer.

Take the Assessment