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American Cancer Society Updates Colon Cancer Screening Guidelines

The American Cancer Society recently updated its colon cancer screening guidelines to say that screening should begin at age 45 for people at average risk instead of age 50, as previously recommended.

To learn more, we sat down with UNC REX gastroenterologist Rig Patel, MD, the medical director of REX Digestive Healthcare.

Why has the guideline changed from age 50 to 45?

The reason the American Cancer Society made the change is that the incidence of colon cancer in younger people is going up very fast. So even though most people who get colon cancer are over the age of 50, the fastest rise in incidence of colon cancer in an age group is between ages 20 and 35, and the total incidence of colon cancer of patients near age 50 is rising. Colorectal cancer incidence rates in adults ages 50 to 54 were half those in adults ages 55 to 59 in the early 1990s, but in 2012 to 2013, they were only 12.4 percent lower for colon cancer and equal for rectal cancer. So people seem to be getting colorectal cancer younger.

So that’s the reason why they’re suggesting that. They think it may have a bigger impact on reducing the death rate from colon cancer—because if you catch it early, colon cancer is curable.

But it’s important to remember this is only a guideline by one society, the American Cancer Society. The GI (gastroenterology) societies have not completely endorsed this change yet. There is a lot of dialogue going on right now among the GI societies regarding this new suggestion. Additionally, at this time, it is unclear whether the insurance companies are going to cover the age reduction.

Why do you think people are getting colon cancer at a younger age than before?

We think there are lots of factors, environmental ones being the most significant: eating a lot of red meat or processed meat, lack of fruit and vegetables, eating a high-fat diet, smoking, not exercising and being obese. There’s also a higher incidence of diabetes and obesity in the population. Genetic factors may also play a role.

Do you agree with this new screening guideline?

That’s a tough one to answer without looking at data. Whenever you put a screening test into place, you’ve got to look at the cost of the screening program and the benefit and risks of that screening test, as well as the incidence of the disease you are screening for. If you take out cost, yes, I would definitely say it’s a good idea, as we are seeing a trend of more colon cancer and colon polyps in younger adults than we did 20 years ago.

But right now, I think we need to look at what the population data is going to show. What do we think is the true impact of lowering the screening age?

We just don’t know for sure, but we are concerned enough that this discussion needs to happen. In the meantime, we are very carefully evaluating younger patients with any suspicious symptoms such as bleeding, anemia or change in bowel habits, many of whom will have a colonoscopy.

The American College of Gastroenterology has always endorsed that the African-American population start screening at age 45. We definitely recommend that. Also, anyone who has a family history of colon cancer or colon polyps or high-risk disorders that predispose them to colon cancer should definitely start at a younger age. That includes people with inflammatory bowel disease, including ulcerative colitis and Crohn’s disease.

These certain populations, without question, need to start screening below the age of 50; we have enough proof that we feel pretty strongly about that. Whether we want to put that onto everyone who is below 50 years, and if 45 years is an appropriate age to start, is not fully decided. The national gastroenterology and cancer societies will likely be reviewing this very carefully when developing new guidelines directed at the whole population.

What does a colon cancer screening entail?

Colon cancer usually occurs when you develop a small polyp, a tiny little growth, on the inside of the colon. And then over 10 years or more, that polyp gets bigger and bigger and bigger. And the bigger it gets, the higher the risk it has of turning into a cancer.

So if you have a polyp, it doesn’t mean you’re going to get cancer next year. Most people aren’t. It’s just because it’s allowed to grow over years and then develop into cancer. The way you actually reduce the incidence of colon cancer or the way you prevent colon cancer is by removing polyps in the colon.

To determine if you have polyps, there are some detection tests.

For a colonoscopy, we put a camera into the colon. It’s a scope that goes into the colon. It actually visualizes the internal lining of the colon and finds polyps. We like to find the polyps when they’re small because they’re easy to remove and completely benign. And colonoscopy is the only way to find small polyps. So we feel colonoscopy is the most accurate and the gold standard to detect and remove polyps and thus prevent colon cancer.

Everyone’s now talking about Cologuard. While this test does pick up cancers or an advanced polyp, its accuracy in detecting small polyps is not very good.

There is also the CT colonography, which is accurate if a polyp is bigger than 6 millimeters.

And then there’s the FIT test, which is a fecal immunochemical test that detects blood in the stool. This test is only going to detect a polyp that’s big enough that it can bleed. It’s not going to detect a polyp that is small.

What do you say to someone who is hesitant to get screened?

Colon cancer is a common cancer that is not only curable if you catch it early enough, but also preventable by detecting and removing polyps. So there is every reason to get screened. There are a lot of colon cancer survivors out there.

Colon cancer is preventable by removing polyps with colonoscopy, which is the gold standard of screening, but any type of colon cancer screening is better than no screening. Please get screened.


If you have concerns about colon cancer, talk to your doctor. If you do not have a doctor, find one near you.