Age is the single most important risk factor for colorectal cancer. Although colorectal cancer can strike at any age, 91 percent of new cases and 94 percent of deaths occur in individuals older than 50. ASGE recommends screening begin at age 50 for individuals at average risk. For individuals with a family history, screening should begin at age 40, or at an age as recommended by their doctor. Some experts suggest that African-Americans should begin screening at age 45. Individuals with other risk factors such as inflammatory bowel disease may also require earlier screening. Patients should speak with their doctor about when to begin screening.
Colorectal cancer incidence and mortality rates are currently highest in African-American men and women. Those of Eastern European Jewish descent currently also have a higher rate of colon cancer than Caucasian men and women. However, because of disproportionate screening, minorities, particularly African-Americans and Hispanics, are more likely to be diagnosed with colon cancer in advanced stages. As a result, death rates are higher for these populations.
There is increasing evidence that obesity is associated with an increased risk of colorectal cancer. A diet made up mostly of foods that are high in fat, especially from animal sources, can increase the risk of colon cancer. People who are not active have a higher risk of colorectal cancer. Engaging in at least moderate activity for 30 minutes or more on five or more days per week will reduce colon cancer risk.
Recent studies show that smokers are 30 to 40 percent more likely than nonsmokers to die of colorectal cancer. Moderate to heavy use of alcohol, or four or more drinks per week, has also been linked to colorectal cancer.
A personal history of colon cancer or intestinal polyps and diseases such as inflammatory bowel disease -- both chronic ulcerative colitis and Crohn's disease -- increase a person's risk of developing colorectal cancer. Patients with both inflammatory bowel disease and a specific liver disease called primary sclerosing cholangitis (PSC) are at very high risk of colorectal cancer.
A person who has a specific inherited gene syndrome, such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colon cancer (HNPCC), is at increased risk for developing colorectal cancer. People with a strong family history of colon cancer are also at increased risk for developing colorectal cancer.
More Answers from American Society for Gastrointestinal Endoscopy