Colon disease
patient resources

A: Some of the most common risk factors for colorectal cancer are:

• Age. Your risk of colorectal cancer increases with age. About 90% of cases occur in people who are 50 years old or older.⁴ Although rates have declined in people over the age of 50 and are rising in people under 50 years of age.^1,2,4  

• A personal or family history of colorectal cancer or colorectal polyps.^1,2,4,5

• Obesity. "Increased waist circumference in adulthood alone is associated with a 53% increased risk of colon cancer."⁶

• Having inflammatory bowel diseases, such as Crohn's disease or ulcerative colitis or diverticulitis.^1,3

• Ethnic background. Risk factors for the early development of colorectal cancer in young adults (30s and 40s), include people of African or Asian descent.^1,7

• A sedentary lifestyle. A lack of physical activity increases your risk of colorectal cancer. Regular exercise may reduce your risk.⁸

• Smoking increases the risk of developing colorectal polyps two to three times.⁸

• Dietary habits and obesity. Western diets rich in red meat and processed foods may increase your risk for colon cancer.^6,8,9

• Diabetes. Those with diabetes or insulin resistance are at a greater risk for colorectal cancer.¹

A: Colorectal cancer is the third leading cause of cancer-related deaths in the United States.⁶ Colorectal cancer is a common and preventable cancer.¹ In the Western world, the lifetime risk of CRC is around 5%.⁸ In the United States, approximately 145,600 cases of CRC are diagnosed annually.¹ 

A: There are many screening options available, including stool test, flexible sigmoidoscopy, CT colonography (virtual colonoscopy), and colonoscopy.¹ Doctors can identify and remove polyps during a colonoscopy procedure.^{10, 11} Meet with your healthcare provider to discuss whether you should get screened and which screening method is right for you. 

CRC screening also has potential harms. Harms are associated with injury to the colon or other complications related to colonoscopy. The primary harms from screening colonoscopy include perforation and bleeding, which occur more commonly if polypectomy is performed. The harms are small but increase with age, primarily because the possible complications from colonoscopy (bleeding, infection, or a hole in the intestine) increase with age.²

A: Polyps are mushroom-shaped growths that can occur on the inside walls of your colon. They can become cancerous over time, and spread to other areas of the body. About two-thirds of colon polyps are the precancerous type known as adenomas.⁹ However, only 5% of adenomas progress to cancer.⁹

A: Adenoma detection rates are the percent of screening colonoscopies performed by a physician that detect one or more confirmed adenomas or adenocarcinomas (poylps).¹¹

ADR is a quality benchmark used by medical societies. Currently, professional societies recommend adenoma detection rates of 15% or higher for women and 25% or higher for men, as 25% or higher for patients as indicators of adequate colonoscopy.^1,11  Each 1% increase in ADR is correlated with a 3% risk reduction of developing colon cancer^.11 ADR rates vary among doctors and patients can inquire about a physician's ADR rate when selecting a physician.¹¹