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ACS Research Highlights

People Ages 45-49 Are Not Getting Screened for Colorectal Cancer

ACS researchers found that colorectal cancer screening in newly eligible adults is low, with stool tests especially low despite increases during COVID-19.

The Challenge 

In 2018, the American Cancer Society (ACS) was the first health organization to reduce the recommended age to start screening for colorectal cancer from age 50 to 45 for people with an average risk. The decision was based on evidence that the risk of developing colorectal cancer at younger ages was increasing and analysis showed that the benefits of earlier screening outweighed the harms. 

In 2021, more organizations reduced the recommended age to start screening for colorectal cancer at age 45. They were the United States Preventive Services Task Force (USPSTF) and the US Multi-Society Task Force on Colorectal Cancer (USMSTF). 

Studies published since the ACS guideline update have reported:

  • A lower incidence of colorectal cancer
  • Earlier screening is cost effective
  • The rates for detecting polyps (also called lesions) in the first colonoscopy for people 45 to 49 with an average risk were comparable to the rates found in first colonoscopies for people 50 to 54 with an average risk.
  • “Modest” increases in the number of people getting a colonoscopy. Reports described rates of screening were still low up to 2019.

Evidence for Starting Screening at Age 45 Instead of 50

As reported in the ACS 2024 Cancer Facts & Figures, there's a notable rise in colorectal cancer diagnoses among people younger than 50.

In the late 1990s, colorectal cancer was the 4th leading cause of cancer death in both men and women in this age group.

Now, it’s the 1st cause of cancer death in men younger than 50 and the 2nd cause in women that age.

The cause of the rise remains unexplained but likely reflects changes in lifestyle exposures that begin with generations born around 1950.

The question is: Are more people in the new, younger age group (ages 45 to 49), getting screened as recommended since 2019?

Screening Test Options for People with an Average Risk of Developing Colorectal Cancer

The guideline calls for people to talk with their doctor about which type of screening test will be best for them. 

Stool-based tests (called FIT, gFOBT, and DNA-FIT) involve a person collecting one or more small samples of stool at home using a kit ordered by their doctor and sending the sample where the kit instructs.

  • FIT and gFOBT tests check samples for hidden blood, which may be a sign of polyps or cancer in the colon or rectum. These tests need to be done every year. If blood is found in a person’s stool, they will need a colonoscopy.
  • DNA-FIT (Cologuard) tests check for hidden blood and for certain abnormal sections of DNA from polyps or cancer cells. This test needs to be done every 3 years. If blood or DNA changes are found in a person’s stool, they will need a colonoscopy.

Visual exams are done during a colonoscopy, virtual colonoscopy, or a sigmoidoscopy. These procedures take place in a medical facility using instruments or technology that allow the doctor to see the inside of the colon and rectum. Using these screening tools, the doctor can remove polyps and send them for testing. One benefit of a colonoscopy is that it can help prevent cancer by removing polyps before they become cancerous. 

  • Both types of colonoscopies allow the doctor to see the entire length of the colon and rectum. If no polyps are found, experts recommend getting a colonoscopy every 10 years or a virtual colonoscopy every 5 years. If polyps are found, doctors should recommend more frequent tests.
  • Sigmoidoscopy allows the doctor to view the lower part of the colon and the rectum. It’s recommended every 5 years. 

The Affordable Care Act requires private health insurance plans that started after 2010 and Medicare to cover the costs of colorectal screening tests, meaning people shouldn’t have to pay any copays or deductibles. Other regulations call for a colonoscopy after a positive FOBT/FIT test to be covered by insurance without copays or deductibles.


The Research

Jessica Star, MA, MPH, associate scientist II in ACS Surveillance & Health Equity Science, led a study published in the Journal of the National Cancer Institute that used data from the 2019 and 2021 National Health Interview Survey to learn about colorectal cancer screening rates in people ages 45 to 49.

They found that there were no increases in screening prevalence for people ages 45 to 49 between 2019 (when only the American Cancer Society had guidelines for people ages 45 to 49 to start screening) and 2021 (when other health agencies updated the guidelines and the year with the most current screening data). In both years, screening prevalence was about the same, with only 1 out of 5 people in that age group receiving screening.

Here are the key findings about colorectal cancer screening for people with an average risk age 45 through 49 in 2021.

People ages 45 to 49 were not keeping up with regular colorectal cancer screening. 

  • Less than 20% (fewer than 4 million of the eligible 19 million) were up to date with recommended screening in 2021. The screening prevalence remained stable between 2019 and 2021.
More people ages 45 to 49 were up to date with visual tests compared with stool tests.
  • Screening prevalence remained stable for colonoscopies. It was 19.5% in 2019 to 17.8% in 2021.
  • Use of stool-based tests increased by 1.2% between 2019 and 2021, but the use was still very low. In 2021, only 2.4% used a stool-based test, including FOBT and FIT.
Regular screening in people ages 45 to 49 varied based on health insurance, education, and ethnicity in similar patterns as those for people ages 50 to 75.
  • Screening prevalence was lower (7.6%) for people who didn't have health insurance compared to people with private insurance (21.4%). (The study authors note that prevalence was similar between privately insured people and those covered by dual, Medicaid, and other public insurance.)
  • Screening prevalence was lower for people with less than a high school diploma (15.4%) compared to people with a college degree (23%).
  • Screening prevalence was lower for Asian people (13.1%) compared to white people (22%). (The study authors note that it was “encouraging” to find that Black people ages 45 to 49 had similar screening prevalence to White people, even though they are both still low.)
Other ACS researchers who contributed to this study were: Rebecca Siegel, MPH, Adair Minihan, MPH, Robert Smith, PhD, Ahmedin Jemal, DVM, PhD, and Priti Bandi, PhD.

Why It Matters

Findings from this study show that screening for colorectal cancer in newly eligible adults is low. Low prevalence likely results from barriers to screening during the COVID-19 pandemic and because of the short amount of time between more health agencies adopting the lower age recommendation and the time of the National Health Interview Survey.

The pandemic did have at least one positive effect. During that time public health insurance was expanded, which authors identify as a likely reason for the higher screening prevalence in people with dual, Medicaid, or other public health insurance. “Public health insurance expansions may therefore offer the greatest benefit for lower resourced under-screened groups, including uninsured and low-income persons who have the lowest screening rates,” the authors wrote.

ACS researchers also noted that the policies that require health insurance plans to cover the costs of screening, including a colonoscopy after a positive stool test, need to be stronger because health insurers are not following the regulations consistently.

There is little evidence for the most effective interventions for raising screening prevalence in younger adults. However, there is some evidence that outreach efforts that include mailing FIT kits to underserved groups of eligible adults ages 45 to 49 are effective.

Plus, when patient navigators contacted people who had positive results from a stool test, the time between results and a follow-up colonoscopy also improved.