What You Need to Know About the New Colon Cancer Screening Guidelines

Doctor consulting with a patient.

The American Cancer Society (ACS) has just updated its guidelines for colon cancer screening, calling on American’s to get tested 5 years earlier than before. Colon cancer is the second leading cause of cancer death, but catching this slow-growing cancer early can lead to prevention. The new guidelines recommend that adults with normal risk start getting tested at age 45 and up until age 75, rather than the society’s previous recommendation of age 50. The ACS recommends people between 75 and 85 should have a conversation about the risks and benefits of screening with their doctors and because the cancer is so slow-growing people over 85 should not have the test.

Why the change? Well, while over the last ten years the rates of colon cancer have been declining for people over the age of 50 (largely due to screening), for younger American’s, cases have actually been on the rise. In fact, according to a recent study in the Journal of the National Cancer Institute colorectal cancer diagnosis has been increasing 0.5 to 3% per year for people under the age of 50. According to the ACS, that means that for those born in 1990 have double the risk of colon cancer and quadruple the risk of rectal cancer compared to those born in the 1950’s. The Cancer Society hopes that earlier testing will help reverse this trend.

No one knows exactly why we’ve seen an increase in colon cancer in people under 50, but we think the reason for this is lifestyle: diet, obesity, inactivity, and the overuse of antibiotics. Another reason is that people often write off the symptoms, especially young people. The main symptoms of colon cancer are:

  • change in frequency, size, and color of stool,
  • rectal bleeding
  • persistent abdominal discomfort like gas, bloating, or cramping
  • weakness or fatigue
  • unexplained weight loss

If you or someone you know have these symptoms no matter what your age you should take them seriously.

People at higher risk may need earlier screening. This includes people with a strong family or personal history of colorectal cancer or certain types of polyps. As well as people with a history of inflammatory bowel disease (ulcerative colitis or Crohn’s disease) or of radiation to the belly or pelvis to treat a prior cancer.

If you are a candidate for screening you have a number of options and you should definitely choose one. The gold standard is a colonoscopy every ten years. If you can’t or won’t get one, there is now a CT colonoscopy. This is a good test, but the disadvantages over a colonoscopy are that it may be hard to read if you have had prior surgery or diverticuli. As a result, it’s recommended every 5 years. You still have to go through the bowel prep to get a CT colonoscopy, so unless your doctor says you can’t have it, you might as well get the real thing. There are also less invasive tests that measure blood or DNA in your stool. These tests can be done at home, but are again not as good as a colonoscopy and need to be done every year.

It’s important to note that the ACS is just one organization that makes recommendations about when to get cancer screening tests. The US Preventive Services Task Force and the American Society of Gastroenterology still recommend that screening begins at 50 for average-risk adults, so we will have to see if the new data leads to changes in their positions as well.

No matter what your risk or your age, the best way to prevent colon cancer is with lifestyle. Some of the most important changes you can make are:

  • Have smaller portion sizes. Portion sizes have grown over time which contributes to overeating and being overweight.
  • Eat more fiber. Fiber is associated with nourishing healthy gut bacteria and can help you lose weight. Some epidemiological suggests that fiber can help prevent colon cancer (but the jury is still out because some studies find no relationship).
  • Eat less processed meat. That’s things like sausages and bacon. According to the WHO processed meat can increase the risk of colon cancer about 18%.
  • Get your calcium. We know that calcium is good for bones, but a number of studies also suggest it can reduce the risk of colon cancer. Both Dr. Oz and I like to get our calcium from Greek yogurt, but leafy greens are also a good source.
  • If your doctor recommends aspirin for your heart, take it. According to the USPSTF aspirin is not only good for your heart, but in people taking it for cardiovascular protection it also may reduce the risk of colon cancer.