CRC Screening Disparities Greatest Among Those Under 55

Tara Haelle

June 29, 2022

Updated July 7, 2022 // Editor's note: This story has been updated with comments from Dr Aparajita Singh of the University of California San Francisco and Dr Reid Ness of Vanderbilt University.

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 and 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 to 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, and his colleagues. "The persistent and worsening disparities we observed in adults 50 to 54 years may extend to those ages 45 to 49 as they become eligible for screening."

The US 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, Texas, 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."

Aparajita Singh, MD, MPH, director of the Hereditary Gastrointestinal Cancer Clinic at the University of California San Francisco, noted that earlier screening might actually have a positive impact on improving screening among those aged 50 and older.

"Earlier messaging starting at age 45 can result in an improved screening rate by 50 years or so, as healthy patients tend to delay initiation of screening by a few years," Singh told Medscape Medical News.

Data Analyzed From 8 Years Over Two 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.

"Asymptomatic younger patients are less likely to be receptive to cancer screening tests, especially those who do not have a family history of cancers," Singh said. "Many younger patients have not undergone sedation or procedures in the past and they may have several misconceptions about colonoscopies." Younger patients may also worry about the risks of sedation or find colonoscopies invasive.

"Primary care providers should customize screening recommendations of colonoscopy vs stool-based tests as preferred by patients," Singh said. "The best colon cancer screening test is the one patient will comply with."

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).

It was the continued lag in colorectal cancer screening rates between different racial/ethnic groups that Reid M. Ness, MD, MPH, an associate professor of medicine at Vanderbilt University Medical Center, found most surprising in the study.

"There is an obvious need for increased efforts in cultural and ethnocentric colorectal cancer screening efforts in these communities," Ness told Medscape Medical News.

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 silver lining is that insurance status seems to be driving factor, and this can be addressed by the successful implementation of a comprehensive national health insurance plan," Ness said. He also noted ways that primary care clinicians can take advantage of systems to improve their patients' screening rates.

"Primary care providers benefit from participation in healthcare networks and the use of electronic health records that provide reminders to them for the application of colorectal cancer screening and surveillance in their patients' care plans," Ness said. "Patients benefit from participation in healthcare systems that employ programmatic colorectal cancer screening services that work in conjunction with all of their providers to insure adequate health maintenance."

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.

In addition to needing time off work, arranging a ride home, and childcare or other caregiving needs, younger adults may also find the cost of the copay prohibitive, Singh said.

"At an individual level, clear messaging from primary care providers, choosing a patient's preferred screening options, and innovative workflow like text reminders can improve screening rates," Singh said. "Community outreach programs can be very effective in reaching the underserved populations."

The most effective way to improve rates across the board, however, remains a robust national healthcare system, Ness said.  

"We need a comprehensive national health insurance plan/system if we are ever to adequately address the glaring inequities in colorectal cancer screening rates related to healthcare access," he said.

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.  Singh reported no relevant financial relationships. Ness is involved in clinical trials with Guardant Health.

Cancer Epidemiol Biomarkers Prev. Published online June 23, 2022. Abstract

Tara Haelle is a Dallas-based science journalist. Follow her @ tarahaelle.

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