Colorectal cancer (colon cancer)

Colorectal cancer (CRC) is the third-most commonly diagnosed cancer and the third leading cause of cancer deaths in the United States, in men and women equally. 150,000 Americans, including nearly 5,000 in the Chicago area, are diagnosed with colon cancer each year. CRC generally develops from colon polyps. Most cases can be prevented by screening (early detection before there are symptoms) and removing colon polyps before they have a chance to grow into CRC. However, about one in three adults are not getting checked for as recommended. If they did, about 30,000 lives would be saved each year – about the number of people killed in car accidents. Illinois gets an ‘A’ from the National Colorectal Cancer Research Alliance, and as in other states, Illinois patients with private insurance will not be liable for cost sharing when a precancerous colon polyp is removed during screening colonoscopy.

Symptoms

• Anemia (low blood count)
• Weight loss
• Blood in the stool
• Constipation or diarrhea
• Narrower stool than normal
• Abdominal pain, bloating, or cramps

In many cases, there are no symptoms – which is why so many Americans put off screening colonoscopy, and diagnoses are missed.

Risk factors

• Age over 50 (or 45 in African-Americans)
• Colon polyps (growths)
• Family history of colon polyps or cancer (although 80% have no such history)
• Inflammatory bowel disease (Crohn’s disease or ulcerative colitis)
• High fat diet
• Obesity and diabetes
• Sedentary lifestyle
• Tobacco use
• Alcohol use

Screening and prevention

Early detection is important. Screening means testing healthy people who have no symptoms at all. Although it is counterintuitive to have a test when there are no symptoms, testing at the recommended schedule saves lives. There has been a 30% decline in colorectal cancer over the last 10 years.

Screening schedule

• Men and women at average risk should start at age 50
• African-Americans should start at age 45
• Those with a family history of colorectal cancer or polyps should start at age 40 or 10 years before the youngest case in the immediate family
• Those with inherited cancer syndromes should begin as young as age 10
• Those with inflammatory bowel disease (Crohn’s disease or ulcerative colitis) should begin within years of diagnosis, to be recommended by a gastroenterologist
• Those with prior polyps or cancer will need more frequent colonoscopies, to be specified by the gastroenterologist based on pathology results and guidelines

A detailed schedule from the American Cancer Society can be found here.

Screening tests

The available tests differ in preparation and in effectiveness.

Some Detection Tests for finding colon cancer are:

• Computed tomography (CT) colonography: this CAT scan does involve radiation exposure. It requires a bowel preparation; if polyps are suspected, a colonoscopy will be necessary.
• Stool tests: the US Preventive Services Task Force (USPSTF) has labeled these as inferior in detection ability, and a colonoscopy will have to be performed if a polyp is suspected. Bowel preparation is not needed.

The only Prevention Test for colon cancer is colonoscopy. Colonoscopy does require a bowel preparation. Unlike the Detection Tests, colonoscopy is highly accurate, and can remove the polyps that are found so that they do not grow into colon cancer. Colonoscopy holds the highest recommendation for colon cancer screening from the USPSTF and American College of Gastroenterology.

Colonoscopy is an outpatient procedure, meaning that it does not require an overnight stay.