Capsule endoscopy has better diagnostic yield than CT colonography
Capsule endoscopy was comparable or superior to CT colonography as a colorectal neoplasia screening test, according to research published in Gut.
Brooks D. Cash, MD, of The University of Texas Health Science Center at Houston, and colleagues wrote that offering different methods of colorectal cancer screening, like capsule endoscopy, increases screening adherence.
“The inherent similarity of test characteristics between colon capsule endoscopy and CT colonography — both are non- invasive or minimally invasive, non-therapeutic imaging modalities — make both tests potentially attractive screening tests for patients at average risk for CRC who decline optimal colonoscopy or stool-based screening options,” they wrote. “To date, no studies have compared the two tests in an average-risk CRC screening population.”
Researchers compared the two screening methods in a randomized trial known as the TOPAZ study. They randomly assigned patients (n = 286) aged between 50 and 75 years — as well as Black patients aged between 45 and 75 years — to undergo screening with either capsule endoscopy or CT colonography followed by a subsequent blinded colonoscopy.
The primary endpoint of the study was diagnostic yield of polyps at least 6 mm in size with either screening method.
Patients who underwent capsule endoscopy had more polyps sized at least 6 mm than patients who underwent CT colonography (31.6% vs. 8.6%; pPr non-inferiority and superiority = 0.999). For polyps at least 10 mm in size, the capsule had a diagnostic yield of 13.5% compared with 6.3% for the CT colonography (pPr non-inferiority = 0.9954).
Additionally, the capsule had a sensitivity and specificity of 79.2% and 96.3% for polyps of at least 6 mm, compared with 26.8% and 98.9% for CT colonography. For polyps of at least 10 mm, they were 85.7% and 98.2% compared with 50% and 99.1%, respectively.
“Both capsule endoscopy and CT colonography had lower sensitivities than colonoscopy for polyp detection, although capsule endoscopy had a diagnostic yield that was comparable with colonoscopy while CT colonography did not,” Cash and colleagues wrote. “Based on these data, capsule endoscopy should be considered a relevant CRC screening option in an average risk population in line with a ranking comparable with or higher than CT colonography, as well as a first-line imaging test after incomplete colonoscopy.”