The U.S. Preventive Services Task Force issued new guidelines in May that recommend screening for colorectal cancer starting at age 45, rather than 50 as previously advised. The lower-age recommendation comes in response to a worrying uptick in diagnoses among middle-aged Americans.

When it comes to screening for colorectal cancer, 45 is the new 50.

Citing a rising incidence of colorectal cancer among middle-aged adults, the U.S. Preventive Services Task Force (USPSTF) issued new guidelines in May that call for routine testing for the disease to start at age 45, rather than at 50 (JAMA 2021;325:1965–77).

Currently, only about half of American adults undergo colorectal cancer screening by their 55th birthday—that is, within 5 years of the recommended starting age under the old guidelines. “So, there's a hope that, by dropping the age to 45, people will start screening earlier and that we will have a bigger impact on the burden of disease,” says Robert Smith, PhD, senior vice president for cancer screening at the American Cancer Society (ACS), who played no role in the USPSTF decision.

Screening can detect precancerous polyps or localized tumors that can be removed to prevent more advancedcolorectal cancer. The USPSTF guidelines offer a menu of screening options, including three stool-based methods—fecal occult blood testing, fecal immunochemical testing, and stool DNA testing—and three direct visualization techniques—colonoscopy, computed tomography colonography, and flexible sigmoidoscopy.

Recommended screening frequency ranges from 1 to 10 years, depending on the testing method. The task force advises follow-up with a colonoscopy, the gold standard, if other tests uncover abnormalities.

The lower-age recommendation comes in response to a worrying uptick in colorectal cancer diagnoses among middle-aged Americans. A decade ago, only 5% of colon cancers and 9% of rectal cancers were diagnosed in patients younger than 50. By 2020, those numbers had risen to 11% and 15%, respectively, with increased screening among the over-50 set putting downward pressure on incidence rates overall but unfavorable dietary patterns and sedentary lifestyles driving up numbers in younger adults.

A modeling analysis commissioned by the USPSTF found that initiating screening at 45 could prevent early deaths, with only a small increase in testing-related complications (JAMA 2021;325:1998–2011). Across all subgroups of sex and race, the modeling indicated that a drop in screening age yielded a favorable balance of benefit versus burden. That calculus held to age 75. After that, screening offered only marginal gains, leading the USPSTF to maintain its prior recommendation of selectively testing older individuals based on their health and screening history.


The new recommendations align with previous position statements from the ACS, the American College of Gastroenterology, and other groups, but they carry greater weight because all U.S. health service companies are required to offer preventative procedures endorsed by the USPSTF at no cost to patients.

With colorectal cancer diagnoses on the rise among people younger than 45, some experts have begun to ask whether even earlier routine screening may be needed. Smith says those discussions are premature, but “if the incidence under the age of 50 continues to rise, then it's not improbable that, at some time in the future, the burden of disease will reach the point where 45 is no longer the new 50—40 will be the new 50.” –Elie Dolgin

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