Screening for colorectal cancer should start at age 45, five years earlier than is currently recommended, according to draft guidelines from the U.S. Preventive Services Task Force.
The update was prompted by recent studies showing the rate of colorectal cancer rising in younger people, according to the draft, published Tuesday.
“Recent studies showing a rising incidence in individuals aged 45 to 49 drew our attention to that age group,” Dr. John Wong, a member of the task force and the chief scientific officer at Tufts Medical Center, said.
Colorectal cancer is the third leading cause of cancer deaths in the U.S.
It’s estimated that 10.3 percent of new colorectal cancers occur in people under age 50 and recent data suggest that 45-year-olds with an average risk are getting colon cancer at rates now similar to 50-year-olds, Wong said.
The draft guidelines fall in line with recommendations issued by the American Cancer Society two years ago. But with the added task force imprimatur, colonoscopies and other colon cancer tests for people ages 45 to 49 are far more likely to be covered by insurance, experts said.
Dr. Otis Brawley, a professor of oncology and epidemiology at the Johns Hopkins School of Medicine and the Johns Hopkins Bloomberg School of Public Health, said the new recommendations were “exciting.”
“The USPSTF tends to be the most conservative and orthodox group in their interpretation of the scientific literature and they rarely make a big change like this,” said Brawley, who isn’t a part of the task force. “They are seeing the same thing the American Cancer Society sees.”
The task force also highlighted the fact that Black Americans are more likely to develop and to die from colorectal cancer than other racial and ethnic groups. From 2013 to 2017, the incidence rates for colorectal cancer were 43.6 cases per 100,000 Black adults, compared with 37.8 cases per 100,000 white adults and 33.7 cases per 100,000 Hispanic/Latino adults.
During the same time period, death rates were 18.5 deaths per 100,000 Black adults, 13.6 deaths per 100,000 white adults and 11.1 deaths per 100,000 Hispanic/Latino adults.
These disparities are not likely a function of differences in biology, Brawley said, but rather are most likely driven by factors such as obesity and poverty.
“There’s a lot of data to suggest that obesity causes colon cancer in Black women,” Brawley said, adding that 60 to 65 percent of Black women in their 20s and 30s are obese as compared to 35 percent of white women.
There’s also the issue of access to care.
“There’s data showing that screening with colonoscopy is not as good in poor people as it is in middle class people,” Brawley said, and Black Americans are more likely to fall below the poverty line.
The explanation: colonoscopists who treat poor people often have to do more procedures per day than those who treat middle-class patients, Brawley said. Further, he said, they tend to look at fewer lymph nodes — sites where cancers spread to quickest — in Black people than in white people. “That means Blacks are often not staged as well,” he said. So, a Black patient with an advanced cancer gets a diagnosis of disease that is less far along.
According to the draft guidelines, one quarter of adults between the ages of 50 and 75 had never had a colon cancer screening. In part, that could be because people don’t want to get colonoscopies, Brawley said. That might be remedied if doctors suggested stool tests as an option.
“The data show that stool-testing every year saves lives,” Brawley said, adding that “the data on stool testing is actually stronger than the data on colonoscopy.”
The task force recommendations support screening via colonoscopy or stool-based tests. There’s no question that both can prevent colon cancer deaths, Wong said, adding that it just comes down to patient preference which method is used.
While the new guidelines are likely to catch more colon cancers earlier, they won’t catch every case, because some people develop the disease at a much younger age. The actor Chadwick Boseman, for example, died of the cancer at 43.
The guidelines are for screening people with no symptoms, said Dr. John Rhee, a clinical assistant professor at the University of Pittsburgh and a medical oncologist at the UPMC Hillman Cancer Center. In younger people, attention to symptoms may be the key to catching the disease earlier, he said.
“While the majority of cases are in people older than 50, we certainly see it in younger people,” Rhee said. “Symptoms of colon cancer can include blood in the stool, abdominal pain, unexplained weight loss, fatigue and anemia. If you have symptoms, you shouldn’t blow them off. You should discuss them with your provider to determine if it’s anything serious or warrants testing.”
CORRECTION (Oct. 27, 2020, 1:30 p.m. ET): A previous version of this article misstated Dr. John Wong's title. He is chief scientific officer at Tufts Medical Center, not chief medical officer.