CT colonography feasible than DNA stool testing in colorectal cancer screening: Study

A new study published in the journal of Radiology showed that CT colonography (CTC) is more efficient and might be more cost-effective than multitarget stool DNA (mt-sDNA) testing, in the context of cancer screening.

The most common method of colorectal cancer (CRC) screening in the US is still optical colonoscopy (OC), which offers both cancer detection and prevention. With OC being the de facto treatment standard for positive cases, less intrusive CRC screening tests offer an additional, complementary option to population-based screening. With proper screening, colorectal cancer may be cured or prevented in most cases. Thus, this study assessed the clinical and financial efficiency of multitarget stool DNA (mt-sDNA) testing with CT colonography screening for colorectal cancer.

Using updated natural history data for colorectal polyps applied to a fictitious 10,000-person cohort representative of the 45-year-old U.S. population, a state-transition Markov model was built. These data were used to model three screening strategies: mt-sDNA testing every 3 years, the surveillance CTC (CTCsurv) strategy of 3-year CTC follow-up for small polyps (6 to 9 mm) and polypectomy for large polyps (≥10 mm), and the conventional CTC (CTCconv) strategy of immediate polypectomy for all polyps measuring at least 6 mm every 5 years. To verify robustness, a multifaceted validation of the model was conducted. Along with the base-case scenario, a thorough sensitivity analysis was carried out.

The cumulative incidence of colorectal cancer (CRC) was 7.5% (n = 752) without screening, but it was lowered by 59% (n = 310) with mt-sDNA screening, 75% (n = 190) with CTCconv screening, and 70% (n = 223) with CTCsurv screening. For no screening, mt-sDNA, CTCconv, and CTCsurv, the anticipated programming expenses per individual were $4955, $6011, $4422, and $3913, in that order.

While both CTC techniques led to cost reductions, the estimated cost per quality-adjusted life year (QALY) obtained for mt-sDNA testing was $8878. As a result, CTC techniques outperformed both mt-sDNA and no screening (i.e., more cost-efficient [cost-saving] and clinically successful). The expenditures associated with additional optical colonoscopies, however, did not balance the modest increases in QALYs, making the CTCconv method less cost-effective than the CTCsurv strategy.

Overall, both CTC screening approaches produced cost savings and improved clinical effectiveness when compared to mt-sDNA screening and no screening. The greatest overall balance between cost and clinical effectiveness was attained by the CTC method, which consists of colonoscopy referral for big polyps and 3-year monitoring for minor colorectal polyps.

Reference:

Pickhardt, P. J., Correale, L., & Hassan, C. (2025). CT colonography versus multitarget stool DNA test for colorectal cancer screening: A cost-effectiveness analysis. Radiology, 315(3), e243775. https://doi.org/10.1148/radiol.243775