Colorectal Cancer

These cancers develop when malignant cells invade tissues of the colon or rectum.

Colon cancer begins in the part of the digestive system that includes the 5-foot-long colon, or large bowel. The remaining part of the large intestine is 6 to 8 inches long, and includes the rectum and anal canal, where cancer can also develop.

Wilmot Cancer Institute has a vibrant, leading program in colorectal cancer. We do gene testing on all biopsies; we use newer medical approaches to minimize the impact of colorectal surgery; our surgeons are well-versed in the most advanced procedures; and we offer clinical trials.

Colorectal cancer types

More than 95 percent of colorectal cancers are adenocarcinomas. They often begin as growths called a polyp. However, gastrointestinal stromal tumors and sarcomas can also start in the colon.

Colorectal cancer facts

More than 132,000 people are diagnosed annually. Colorectal cancer is the second leading cause of death from cancer in the U.S. and the third most common type of cancer diagnosed in men and women. About 90 percent of colon cancers are curable when detected early, and yet less than half of U.S. adults get routine screening for early detection.

Causes and risk factors

The lifetime risk for developing colorectal cancer is about 1 in 20. Age, family history, lifestyle, and having colon polyps are all risk factors.

Among the risk factors that cannot be changed:

  • Age is important because about nine out of 10 people diagnosed are at least 50 years old.
  • Some people have inherited gene syndromes predisposing them to colorectal cancer. African Americans have the highest rate of colorectal cancer in the U.S., for example, and Jews of Eastern European descent have one of the highest risks of any ethnic group in the world.
  • Colorectal cancer is more common in people who have a personal or family history of polyps, or a personal history of inflammatory bowel disease, including Crohn's disease or ulcerative colitis.

Several lifestyle factors linked to colorectal cancer are controllable:

  • Eating a diet rich in red meat or processed meats is associated with this type of cancer. Also, consider the way meat is cooked: very high temperatures used in grilling and frying can raise the risk of colorectal cancer.
  • Lack of exercise and obesity increases the risk.
  • Smoking and heavy alcohol use also boosts the risk of colorectal cancers.


Regular colorectal screening with colonoscopy is the most important way to prevent this slow-growing cancer, because removing colorectal polyps found during a screening may prevent full-blown disease. Other prevention strategies include:

  • Quitting smoking, eating a healthy diet with fiber, exercising, and limiting alcohol intake to less than three drinks a day.
  • Genetic screening for people with a strong family history.
  • Research also shows that taking aspirin daily might be protective. However, aspirin therapy carries other risks and should be discussed with a physician.
  • In older women, studies have shown that hormone replacement therapy might prevent or lower the risk of colorectal cancer. But the possible harms of initiating hormone therapy include breast cancer, heart disease and blood clots. It’s important to speak to your doctor about the risks versus benefits.

Nationally, a handful of clinical trials are taking place for the prevention of colon cancer. Investigators are studying the use of fish oil, medications, and vaccines, for example.