CT colonography (CTC) appears to be cost-effective and accessible for colorectal cancer (CRC) screening in Black adults, researchers have reported.
The findings suggest that CTC used in this capacity could support Medicare coverage of the screening exam, and "address specific population needs and structural barriers to screening," wrote Szu-Yu Zoe Kao, PhD, of Siemens Medical Solutions USA in Malvern, PA, and colleagues from the Harvey L. Neiman Health Policy Institute (HPI). The team's research was published November 12 in Cancer Medicine.
CRC is one of the most common cancers in the U.S., and medical costs for treating it are estimated to be $26 billion in 2025, the group explained. Screening can curtail the disease by finding precursor polyps; screening for CRC includes colonoscopy, CTC, and stool-based tests. Colonoscopy is the most common screening strategy.
Unfortunately, although the overall incidence of CRC has declined, Black adults continue to have higher incidence of the disease than their white counterparts -- which the researchers attribute to "screening access, utilization, and test preference," noting that Black individuals more frequently choose stool-based tests while white adults more often choose colonoscopy.
"This disparity may be due to structural barriers -- such as lack of insurance coverage, limited physician recommendations, or infrequent primary care provider visits -- that limit access to colonoscopy among Black populations," Kao and colleagues suggested.
CTC finds more colorectal adenomas than stool-based tests and offers "colonoscopy equivalent cancer detection," they wrote, noting that Black individuals show "greater willingness to undergo CTC than white adults, highlighting its potential to address racial disparities while maintaining high-quality detection." The test became more accessible in January of this year, when the U.S. Centers for Medicare and Medicaid Services (CMS) began covering screening CTC.
Kao's group sought to evaluate the cost-effectiveness of CTC for colorectal cancer screening by creating a microsimulation model that compared CRC screening strategies in average-risk adults by race and gender, using 2010 to 2019 U.S. data on disease progression and "real-world screening adherence" for colonoscopy and fecal immunochemical testing. The model compared the following five strategies:
- Status quo, that is, a choice between colonoscopy and fecal immunochemical testing
- CTC every five years
- Colonoscopy every 10 years
- Annual fecal immunochemical testing
- Multitarget stool DNA test every three years, with no other screening
The researchers evaluated lifetime costs, quality-adjusted life years gained (QALYG), and incremental cost-effectiveness ratios, and set a willingness-to-pay threshold of $100,000/QALYG.
Their key finding was that, compared to the status quo, the CTC strategy yielded more QALYG and fewer CRC cases among Black adults (although this strategy resulted in fewer QALYG and more CRC cases among white adults). The group also reported that, under the status quo strategy, Black adults showed higher CRC cases and greater utilization for fecal immunochemical testing over colonoscopy compared with white adults and that the status quo and CTC strategies outperformed other strategies across races.
"Analysis of real-world screening adherence shows the CTC-only strategy emerged as the dominant strategy for Black adults, while both the CTC-only and status quo strategies could be optimal for white adults depending on resource constraints," the group concluded. "These racial differences stemmed primarily from disparities in screening adherence in the status quo strategy."
The complete study can be found here.
