The ACS previously recommended that screening begin at age 50 for those who are at average risk for colon and rectal cancer, and at a younger age for people at higher risk and those with a family history of the disease.
Colorectal cancer is a cancer that starts in the colon or the rectum. Colon cancer is cancer of the large intestine (colon), which is the final part the digestive tract. Most cases of colon cancer begin as small, noncancerous or benign clumps of cells called adenomatous polyps. Over time some of these polyps can become colon cancers.
Polyps may be small and produce few, if any, symptoms. For this reason, doctors recommend regular screening tests to help prevent colon cancer by identifying and removing polyps before they turn into cancer.
The American Cancer Society estimates that about 1 in 21 men and 1 in 23 women in the United States will develop colorectal cancer during their lifetime.
The new guideline, published in CA: A Cancer Journal for Clinicians, states: “The ACS recommends that adults aged 45 years and older with an average risk of colorectal cancer undergo regular screening with either a high‐sensitivity stool‐based test or a structural (visual) examination, depending on patient preference and test availability.”
One factor prompting the change was a 2017 study published in The Journal of the National Cancer Institute in which researchers found that compared to adults born around 1950, those born closer to 1990 have double the risk of colon cancer and quadruple the risk of rectal cancer. Additionally, nearly one-third of rectal cancer incidents reviewed in the study were in patients younger than age 55.
Tae Kim, MD, a colorectal surgeon at Intermountain Healthcare’s LDS Hospital and Intermountain Medical Center, thinks the change is important news. He says that while other cancer screenings like mammograms only help to catch early cancer, a screening colonoscopy can catch early signs of cancer, which can stop the disease before it begins.
“We’ve known about the effectiveness of preventive screenings at a younger age for some time,” said Dr. Kim. “It’s good to change the screening guidelines to reflect these concerns. With this new recommendation, we hope we can prevent more cases of colon and rectal cancer in younger patients.”
The data included in the ACS study falls short of predicting what might be causing the increasing colorectal cancer trend, and instead calls for more research to help discover the cause.
As part of the new guidelines, the ACS identified six options for screening tests; three high‐sensitivity stool‐based tests and three structural examinations. Studies suggest that both stool-based colorectal cancer screenings and structural examinations, such as colonoscopy, perform similarly in detecting cancer among individuals younger than 50 years and among older individuals. However, the ACS says all positive results from non-colonoscopy screenings should be followed up with a timely colonoscopy.