The U.S. Preventive Services Task Force, an independent group of physicians that provides guidelines on preventive care, noted that it was especially concerned about increasing cases among Black Americans, who are at higher risk of developing colorectal cancer early and dying from it.

“Black men and women are disproportionately affected, both in terms of the development of colorectal cancer and unfortunately they have lower survival rates with colorectal cancer,” said John Wong, a physician at Tufts Medical Center in Boston and a member of the task force. “That disparity, relative to other racial and ethnic groups, is an important part of our recommendations to lower the screening age at which to start.”

The draft recommendation broadens the group of adults in the U.S. who should receive colorectal screening. Once it is finalized, after a public comment period of four weeks, it will replace the task force’s 2016 guidelines that state adults without risk factors for colorectal cancer should begin screening at age 50 and continue periodically until 75. The task force based the draft recommendations on a review of new peer-reviewed research, including an analysis of the benefits and potential harms of screening.

“We’re seeing just as much colon cancer newly developing in the 45-to-49-year-olds as we used to see in 50-to-54-year-olds,” Wong said. “The evidence suggests that screening is both effective and saves lives.”

About 18,000 people under age 50 will be diagnosed with colorectal cancer in the U.S. this year — 12% of total cases — and more than 3,600 are projected to die, the American Cancer Society estimates. The research the task force examined showed that adults who were 45 in 2016 had a similar incidence of colorectal cancer as people who were 50 in 1992, during a time before colorectal cancer screening was widely used. The reasons for the rise are uncertain.

Under the Affordable Care Act, the task force’s recommendations are used to determine preventive services that insurers must cover at no cost to patients. If the draft recommendation stays as is following the final deliberations, then colorectal screening for people between the ages of 45 and 49 would be covered, said Wong. He noted the task force’s judgements were based on an examination of the clinical science and were not made with consideration to insurance coverage or cost to patients.

Gastroenterologists not involved with the task force welcomed the new recommendations, but noted they will present some challenges.

“What this equates to is about an additional 21 million Americans that will need to be screened,” said Fola May, a gastroenterologist at the University of California, Los Angeles. From a public health standpoint, she said she worries about how to get all of these additional Americans screened. “Colon cancer screening was just one of the measures we as a nation were always poor at and we were especially bad with ethnic and racial minorities, Blacks, Latinos, Asians, and Native Americans.”

While 69% of white adults in the 50-to-75 age group were up to date on colorectal cancer screenings in 2018, according to the American Cancer Society, the rate fell to 66% for Black adults and between 56% and 59% for Hispanic, American Indian/Alaska Native, and Asian adults.

The two screening measures the task force recommends include “direct visualization tests,” like colonoscopies, and stool-based tests that analyze a person’s stool for blood or signs of cancer. The task force noted that after getting screened at 45, a person would have to receive a colonoscopy every 10 years or a stool-based test every one to three years, depending on the test.

“I hope that people will embrace that we should use even the non-invasive methods, like the stool tests,” said May, “and not for everyone to get a colonoscopy because I think that would be virtually impossible.”