When to Start Average Risk Screening

If screening can prevent colorectal cancer and find it early, the question is often asked, “Why not begin screening earlier than age 50?”

You may have friends or family who were diagnosed before they were 50. You, yourself, may have had an early diagnosis. You wonder if screening could have made a difference for you or your friends and family.

The simple answer is that the benefits of prevention and early diagnosis don’t begin to outweigh the risks of population-wide screening for people of average risk until they reach age 50.

Instead, Fight Colorectal Cancer

Supports the recommendations of both the American Cancer Society and the United States Preventive Services Task Force (USPSTF) that screening for average risk individuals begin at age 50.
Encourages all adults to assess their personal and family risk for colorectal cancer and make a plan for earlier or more frequent colonoscopy surveillance where necessary.
Strongly urges evaluation of symptoms of colorectal cancer with colonoscopy at any age.

We know that of the 150,000 new diagnoses each year, less than 1 in 10 is made before the age of 50, fewer than 5 percent or 1 in 20 under the age of 45. The median age for colorectal cancer diagnosis is 71, and its risk increases with aging. We also know that most colorectal cancer develops slowly, with the average time for a polyp to develop into colorectal cancer being about 10 years.

Colonoscopy is an invasive procedure and has risks. Serious problems can occur with the required bowel preparation, sedation, or during the procedure itself. When other less invasive screening methods, including stool testing or CT colonography, are positive, they must be followed up with colonoscopy — even when they prove false.

Serious complications requiring hospitalization occur in about 25 of every 10,000 colonoscopies. Some are fatal. Screening before 50 simply will not avoid enough deaths from colon or rectal cancer to offset these risks, including deaths from screening itself.

The United States Preventive Services Task Force (USPSTF) has the responsibility of recommending health prevention strategies to the American people based on evidence for benefits and harms. In their 2008 colorectal cancer screening recommendations, they write:

Evidence is adequate to estimate the harms of colonoscopy. In the United States, perforation of the colon occurs in an estimated 3.8 per 10,000 procedures. Serious complications—defined as deaths attributable to colonoscopy or adverse events requiring hospital admission, including perforation, major bleeding, diverticulitis, severe abdominal pain, and cardiovascular events—are significantly more common, occurring in an estimated 25 per 10,000 procedures.

The USPSTF examined the balance between colonoscopy risk and additional life-years gained though screening. They concluded,

For all screening modalities, starting screening at age 50 resulted in a balance between life-years gained and colonoscopy risks that was more favorable than commencing screening earlier.

A study from Canada reported in Gastroenterology in December of 2008 looked at colonoscopies performed in community settings and found perforations in 8.5 of every 10,000 procedures and bleeding in 16.4. One person died for every 14,000 colonoscopies.

In that article, research gastroenterologist Dr. Linda Rabeneck concluded,

Although colonoscopy has established benefits for the detection of colorectal cancer and adenomatous polyps, the procedure is associated with risks of serious complications, including death. Older age, male sex, having a polypectomy, and having the procedure done by a low-volume endoscopist were independently associated with colonoscopy-related bleeding and perforation.

But . . . don’t avoid colonoscopy after you are 50!

Although there are risks to colonoscopy, the benefits of preventing colon or rectal cancer outweigh the risks once colorectal cancer and adenoma rates begin to climb after age 50.

Are there other strategies to find colorectal polyps and cancers in younger people?

Fight Colorectal Cancer strongly supports three ways of reducing your risk of dying from colorectal cancer under age 50.

Assess Your Family History: People with a family history of colorectal cancer may need to begin colonoscopy surveillance earlier and do it more often. About 20 percent of colorectal cancer is associated with a family history, and about 5 percent is known to be directly inherited from parent to child. Recognizing genetic or familial risk and planning a strategy to manage that risk is important for some people under 50. Talk to your family about their medical history!
Know Your Own Personal Health Risk: Inflammatory bowel disease, including ulcerative colitis and Crohn’s disease greatly increases colorectal cancer risk. Regular colonoscopies with biopsies need to take place beginning about eight years after diagnosis of these conditions.
Know the Symptoms of Colorectal Cancer: Always have symptoms evaluated with colonoscopy at any age. No one is too young for colon or rectal cancer. Changes in bowel habits, narrowed stools, rectal bleeding, abdominal discomfort, or unexplained fatigue , weight loss,or anemia may be signs of colorectal cancer and should be followed up. Watching and waiting is not an option.