Study Reveals Disparities in Colorectal Cancer Screening

Significantly more younger people underwent colorectal cancer screening after the recommended age to begin such screening was lowered, Yale researchers report.

In a new study of 10 million insured people aged 45 to 49, researchers found that a recommendation by the United States Preventative Services Task Force to drop the age for starting colorectal cancer screening by five years to age 45 was highly effective — tripling the rate of screening overall — but the magnitude of increase was significantly smaller for low-income and rural populations.

The study, by researchers from Yale Cancer Center and the Yale School of Public Health, was published in JAMA Network Open on October 3.

“Despite having health insurance, access to cancer screening services strongly depends on where you live,” said first author Sunny Siddique, a Ph.D. student at the Yale School of Public Health. “For example, residing in a high-income or urban area may enhance your knowledge about colorectal cancer screening or make it easier for you to find a provider.”

New guidance on the recommended screening age was issued in May 2021 by the United States Preventative Services Task Force with the aim of increasing early detection of colorectal cancer, which is the second most common cause of cancer death in the U.S. The previous guidelines recommended screening start at age 50. This change was due to a continuous increase in the incidence of colorectal cancer among Americans under the age of 50.

While more insured people aged 45-49 received screening following the recommendation change, those living in zip codes that were in the top 20% for socioeconomic status saw a nearly 69% higher increase than those residing in zip codes that were in the bottom 20% in terms of socioeconomic status, the study found. Additionally, residents in metropolitan areas experienced a 45% higher increase than those residing in non-metropolitan areas. These findings highlighted a gap in health care equity, researchers said.

“Health insurance is not enough to reduce disparities,” said Siddique. “We need to selectively help people living in low-income and rural areas receive their recommended screening. Identifying and addressing barriers to screening will be key to reducing these disparities.”

Senior author of the study Xiaomei Ma added, “Although it is encouraging to observe a three-fold increase in colorectal cancer screening among the age group of 45 to 49 years, only 11.5% of average-risk individuals eligible for screening after May 2021 received screening before they turned 50.” Ma is a professor of epidemiology at the Yale School of Public Health and co-leader of the Cancer Prevention and Control Research Program at Yale Cancer Center.

“Given the rapid increase in the incidence of colorectal cancer among Americans younger than 50, it is critical to develop and implement initiatives to improve screening for all,” said Ma.

Cary Gross, Rong Wang, Faiza Yasin, Jacquelyne Gaddy, and Lan Zang from Yale were co-authors.