Through advanced research, medical professionals have identified the following risk factors for colorectal cancer:

  • Age: Colorectal cancer is more likely to occur as individuals get older. More than 90 percent of people with this disease are diagnosed after age 50. However, since younger patients can develop the disease, those with symptoms or a family history should be screened earlier. The average age of patients diagnosed with colorectal cancer is 71.
  • Race: African Americans may have an increased risk of developing colorectal cancer.
  • Colorectal polyps: While most polyps are benign, some polyps can become cancerous over time. These are referred to as adenomas. Detecting and removing polyps may reduce the risk of colorectal cancer.
  • Family history of colorectal cancer: Close relatives of a patient with colorectal cancer are somewhat more likely to develop this disease themselves. If many close relatives have a history of colorectal cancer, the risk is even greater.
  • Genetic alterations: Changes in certain genes increase the risk of colorectal cancer.
    • Hereditary nonpolyposis colorectal cancer (HNPCC): This is the most common type of inherited colorectal cancer.
    • Familial adenomatous polyposis (FAP): This rare, inherited condition causes hundreds of polyps to form in the colon and rectum. For adults with this condition, the doctor may recommend an operation to remove all or part of the colon and/or rectum.
  • Family members of individuals diagnosed with hereditary nonpolyposis colorectal cancer or familial adenomatous polyposis can have genetic testing to check for specific genetic changes. For those with changes in their genes, health care providers may suggest ways to help reduce the risk of colorectal cancer, or to improve the chances of detection of this disease.
  • Personal history of cancer: A patient who has already had colorectal cancer may develop the same type of cancer a second time. Also, women with a history of cancer of the ovary, uterus (endometrium), or breast have a somewhat higher risk of developing colorectal cancer.
  • Ulcerative colitis or Crohn's disease: An individual who has had a condition that causes inflammation of the colon, such as ulcerative colitis or Crohn's disease, for many years has an increased risk of developing colorectal cancer.
  • Diet: Medical studies suggest that diets high in fat (especially animal fat) and low in calcium, folate and fiber may increase the risk of colorectal cancer. Also, some studies suggest that people who eat a diet very low in fruits and vegetables may have a higher risk of colorectal cancer. Heavy alcohol use may be associated with an increase in colon cancer risk.
  • Obesity and sedentary lifestyle: Maintaining a healthy body weight and engaging in regular exercise helps promote and sustain an individual’s overall health.
  • Cigarette smoking: Individuals who smoke cigarettes may be at increased risk of developing polyps and colorectal cancer.