Bottom Line: In 2018, Americans aged 50-54 were 30.4 percent less likely to meet recommended colorectal cancer screening guidelines than Americans aged 70-75 and faced higher screening disparities based on race, ethnicity, household income, educational attainment, and insurance coverage.
Journal in Which the Study was Published: Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research
Author: Caitlin Murphy, PhD, MPH, an associate professor at the UTHealth School of Public Health
Background: In May 2021, the U.S. Preventive Services Task Force (USPSTF) updated their guidelines to recommend colorectal cancer screening for all individuals beginning at age 45—five years earlier than the previous recommendation. The change was based on the rising incidence of colorectal cancer in adults younger than 50; according to federal statistics, individuals aged 45-54 accounted for 15.1 percent of colorectal cancer cases and 9.2 percent of colorectal cancer deaths from 2015 to 2019.
Because younger individuals face unique barriers to screening, Murphy and colleagues sought to predict screening disparities that may arise in the new age group by looking at screening patterns in the previously youngest age group—those aged 50-54. Such barriers include work and family demands, insufficient insurance coverage, and fewer overall health care visits, which may disproportionately affect racial and ethnic minorities and socioeconomically disadvantaged individuals, Murphy said.
“The disparities in screening that have been observed among older adults may extend to adults aged 45-49 as the new USPSTF recommendations are implemented,” she continued.
How the Study was Conducted: The researchers used data from the National Health Interview Survey (NHIS), a comprehensive annual health survey administered by the U.S. Centers for Disease Control and Prevention (CDC) to a diverse group of American participants. Colorectal cancer screening participation was assessed during eight discontinuous years between 2000 and 2018, and data from these eight years were included in the study.
The study population consisted of 80,220 participants aged 50-75 with complete colorectal cancer screening information and no personal history of colorectal cancer. Screening was self-reported and defined as a stool-based test within the past year, a fecal immunochemical DNA test within the past three years, colonography or sigmoidoscopy within the past five years, or colonoscopy within the past 10 years.
Results: Colorectal cancer screening participation increased over time, but the increase was smallest among individuals aged 50-54—a change from 28.2 percent in the year 2000 to 47.6 percent in the year 2018. In contrast, screening for individuals aged 70-75 years increased from 46.4 percent in the year 2000 to 78.0 percent in the year 2018.
In 2018, larger screening disparities were observed between individuals of different racial and ethnic groups, education levels, household income, and health insurance coverage among individuals aged 50-54 as compared with individuals aged 70-75. Notable differences include:
- For Hispanic individuals, screening was 15.5 percent lower than for non-Hispanic white individuals aged 50-54, but the difference was 0.3 percent for those aged 70-75.
- For Asian individuals, screening was 17.7 percent lower than for non-Hispanic white individuals aged 50-54 but 9.4 percent lower for those aged 70-75.
- For individuals with less than a high school diploma, screening was 24 percent lower than for individuals with a bachelor’s degree or higher aged 50-54 but 13.9 percent lower for those aged 70-75.
- For uninsured individuals, screening was 43.4 percent lower than for individuals receiving military insurance aged 50-54 but 1.2 percent lower for those aged 70-75.
Author’s Comments: These data, Murphy said, demonstrate that many screening disparities are concentrated in younger age groups, and she suggested that similar problems may be observed in individuals aged 45-49 under the new guidelines. Though she emphasized that it may take several years for data from the new guidelines to become available, Murphy urged additional research into barriers to screening among younger adults and how to implement evidence-based interventions to increase screening for those individuals.
“Across all age groups, colorectal cancer screening participation remains below national goals, and the benefits of screening are not equally realized across populations,” Murphy said. “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.”
Study Limitations: Limitations of this study include self-reporting of screening behaviors via survey, as well as a lack of data concerning individuals with elevated colorectal cancer risk.
Funding & Disclosures: This study was funded by the National Institutes of Health and the Cancer Prevention and Research Institute of Texas. Murphy is a consultant for Freenome.
Learn more about the latest cancer health disparities research, key facts and figures related to cancer disparities, and the AACR’s advocacy for health equity in the AACR Cancer Disparities Progress Report 2022.