CT Colonography Outperforms Stool DNA Tests in Colorectal Cancer Screening

Recent research published in Radiology highlights the advantages of CT colonography (CTC) over multitarget stool DNA (mt-sDNA) testing for colorectal cancer screening. The study, conducted by Perry J. Pickhardt, M.D., from the University of Wisconsin, utilized a comprehensive model to compare the clinical effectiveness and cost-efficiency of these two minimally invasive screening methods. The results demonstrated that CT colonography reduces colorectal cancer incidence by approximately 70-75%, outperforming the 59% reduction achieved by stool DNA testing. Cost analysis revealed that while stool DNA testing is cost-effective, at roughly $9,000 per quality-adjusted life-year (QALY), CT colonography is actually cost-saving, offering better prevention outcomes at a lower expense.

Colorectal cancer remains the second leading cause of cancer-related deaths globally. Routine screening allows for early detection and removal of precancerous polyps, significantly decreasing the likelihood of cancer development and the need for more aggressive treatments. Recently, health authorities in the U.S. have lowered the recommended screening age to 45 years due to rising cases among younger populations.

Although colonoscopy remains the gold standard for its ability to remove polyps during the procedure, its invasiveness and higher costs limit its widespread use. As a result, less invasive options such as stool DNA tests and CT colonography have become more prevalent, especially with expanded Medicare coverage. Both options are considered safe, effective, and accessible, with CT colonography additionally offering extracolonic screening for conditions like osteoporosis and cardiovascular disease.

The study utilized a simulated cohort of 10,000 individuals aged 45–75, assuming full adherence to screening schedules. Findings conclusively favored CT colonography for its superior effectiveness in preventing cancer and its cost benefits. The results particularly emphasized a hybrid approach involving surveillance for small polyps and direct colonoscopy for larger ones, optimizing both health outcomes and cost efficiency.

Dr. Pickhardt underscored that among minimally invasive screening options, CT colonography provides a more effective and economical strategy compared to stool DNA testing. This modality not only enhances early detection but also broadens screening scope through additional health checks, making it a promising choice for population-wide colorectal cancer prevention.

For more detailed insights, see the full study: [Radiology, 2025].

Source: https://medicalxpress.com/news/2025-06-ct-colonography-stool-dna-colon.html