Adults younger than 55 years were least likely to get screened for colorectal cancer over the past 2 decades, particularly if they were Hispanic or Asian or had a low income, lower education level, or no health insurance, according to a new study published online in Cancer Epidemiology, Biomarkers & Prevention.
The findings have raised concerns that disparities in screening rates will be even greater in adults aged 45-49 years, prompting the need for increased awareness and outreach to ensure that underserved groups have access to screenings.
“Differences in prevalence of screening by race and ethnicity, educational attainment, household income, and health insurance were most pronounced for those ages 50-54 years, whereas older adults experienced larger increases in prevalence across these groups,” wrote Po-Hong Liu, MD, MPH, a clinical investigator at Harvard University, Boston, and his colleagues. “The persistent and worsening disparities we observed in adults 50-54 years may extend to those ages 45-49 as they become eligible for screening.”
The U.S. Preventive Services Task Force shifted their recommendation for colorectal cancer screening in May 2021 to 5 years earlier, advising people to start screenings at 45 instead of 50, which aligns with the recommendations the American Cancer Society made 3 years earlier.
Both organizations made the change because of increasing rates of colorectal cancer in adults under age 50 and research indicating that beginning screenings at age 45 results in fewer cases, fewer deaths, and more life years gained.
“Across all age groups, colorectal cancer screening participation remains below national goals, and the benefits of screening are not equally realized across populations,” senior author Caitlin Murphy, PhD, MPH, associate professor, UTHealth School of Public Health, Houston, said in a prepared statement. “Extra care must be taken to ensure that expanding screening to younger ages does not negatively impact efforts to eliminate disparities in colorectal screening and outcomes nor jeopardize efforts to increase screening initiation among older adults who remain unscreened.”
Data analyzed from 8 years over 2 decades
The researchers analyzed data from the CDC’s cross-sectional National Health Interview Survey during 8 years over the past 2 decades: 2000, 2003, 2005, 2008, 2010, 2013, 2015, and 2018.
The number of participants each year ranged from a low of 21,781 in 2008 to a high of 34,557 in 2013. After excluding participants with a history of colorectal cancer or missing information on screenings, the total population sample included 80,220 participants 50-75 years old.
The researchers considered a person as having been screened if they received at least one recommended screening test within the year covered by the survey, regardless of why they underwent the test.
Recommended tests included sigmoidoscopy, colonoscopy, and stool-based tests for all survey years. In addition, the surveys for 2010, 2015, and 2018 included CT colonography, and the 2018 survey included FIT-DNA.
Screening across population groups
Colorectal cancer screening rates have doubled in the past 2 decades, from 36.7% in 2000 to 66.1% in 2018.
Rates are considerably lower, however, for several key groups, including the youngest group. Less than half (47.6%) of those aged 50-54 years received screenings in 2018, though this was still a nearly 20-point improvement over the 28.2% in this age group who were screened in 2000.
Separate from age, several other groups continue to have low screening rates in general, including Hispanics (56.5%, up from 25.9% in 2000), Asians (57.1%, up from 22.6% in 2000), those who have not received a high school degree (53.6%, up from 26.8% in 2000), and those from low income families (56.6%, up from 30.2% in 2000).
The group with the greatest need for more outreach and screenings are people without insurance, only 39.7% of whom were screened in 2018, a modest increase from 30.2% in 2000.
The biggest increase in screenings over time occurred in those aged 70-75 years, from 46.4% in 2000 to 78% in 2018 overall.
Racial/ethnic, economic, education, and insurance-based disparities were particularly evident the younger people were, including in terms of progress made over time.
For example, screenings of non-Hispanic White people aged 50-54 years improved 21 points (30.3% to 51%) between 2000 and 2018, compared with 19 points in Hispanics (16.7% to 35.5%) and 15 points in Asians (17.3% to 32.3%). Fortunately, Black Americans made even greater strides than White Americans with a 27-point increase during that time (23.4% to 50%).
Similarly, income correlated with expansion in screening rates for 50- to 54-year-olds: Those earning at least 400% over the federal poverty line improved 20 points (from 33.5% to 53.8%), compared with a 16-point improvement in those earning less than 200% above the poverty line (from 19.3% to 35%).
Those with private insurance likewise improved 21 points (from 30.7% to 51.7%), while those in this age group without insurance declined, with just 21.2% getting screened in 2018, compared with 28.2% in 2000. Those on public insurance saw a 15-point improvement, from 27.8% in 2000 to 43.1% in 2018.
“The individual and societal burden of colorectal cancer is especially great among younger adults,” the authors wrote.
The reasons for the much lower prevalence of screening in those under 55, the authors suggested, is likely due to less concern about colorectal cancer, less access to medical care (including being underinsured or uninsured), and the barriers created by competing priorities, such as work schedules, family responsibilities, and caregiving. The latter may be particularly true in underserved populations, the authors noted.
“Screening programs must consider the barriers unique to younger adults, ensuring the benefits of screening are equally realized by all population groups,” the authors concluded.
The research was funded by the National Institutes of Health and the Cancer Prevention and Research Institute of Texas. One author reported grants from Epigenomics and Freenome and personal fees from Guardant Health. Another author reported personal fees from Freenome, and a third author reported personal fees from Exact Sciences. No other authors had industry disclosures.
A version of this article first appeared on Medscape.com.
