Study data published in Gut describe the diagnostic performance of colon capsule endoscopy (CCE) and computed tomographic colonography (CTC) for the detection of colorectal cancer (CRC). In a randomized clinical trial of a screening population, CCE was found to outperform CTC for the detection of polyps ≥6 mm and was found to be noninferior for the detection of polyps ≥10 mm. These results support the consideration of CCE as a relevant cancer screening option.
This study enrolled adult patients from medical centers across the United States. Eligible patients were 50 to 75 years of age and classified as be at average risk for CRC. Patients with a medical or family history of CRC were excluded from participation. Enrolled patients were randomly assigned 1:1 to undergo CRC screening by either CCE or CTC.
All patients underwent optical colonoscopy within 5 weeks of initial screening to confirm any polyp diagnoses. The primary endpoint was the diagnostic yield of CCE compared with CTC. Diagnostic yield was defined as the proportion of individuals correctly diagnosed with any polyp or mass lesion ≥6 mm with CCE vs CTC. Secondary endpoints included the relative sensitivities and specificities of CCE and CTC. Adverse events were monitored throughout the trial duration.
A total of 286 patients had complete trial data, among whom 145 underwent CCE and 141 underwent CTC. In the total cohort, mean age was 55.7±5.68; 57.7% were women; 78.3% were White; and 19.6% were Black. Demographic and clinical characteristics were generally similar between the CCE and CTC arms. However, the CCE arm had a greater proportion of women (63.4% vs 51.8%; P =.046) and a higher mean body mass index (32.2 vs 30.2; P =.018) compared with the CTC arm.
The proportion of patients with a polyp ≥6 mm confirmed by colonoscopy was 31.6% in the CCE group vs 8.6% in the CTC group. The diagnostic yield with optical colonoscopy was 27.6%. Per these figures, the posterior probabilities (pPr) of CCE being noninferior and superior to CTC were both 99.99%. The diagnostic yield for polyps ≥10 mm was 13.5% in the CCE group vs 6.3% in the CTC group (noninferiority pPr: 99.94%; superiority pPr: 98.35%). The sensitivity and specificity of CCE for polyps ≥6 mm were 79.2% and 96.3%, respectively. In the CTC group, these figures were 26.8% and 98.9%. For polyps ≥10 mm, the sensitivity and specificity of CCE was 85.7% and 98.2% compared with 50.0% and 99.1% for CTC. Both the CCE and CTC conditions were well tolerated by patients.
Per these results, CCE was found to be superior to CTC for the detection of polyps ≥6 mm and noninferior for the detection of polyps ≥10 mm. Standard optical colonoscopy outperformed both modalities for the detection of polyps. However, CCE had a diagnostic yield that was comparable to optical colonoscopy (31.6% vs 27.6%), while CTC did not. “Based on these data, CCE should be considered a relevant CRC screening option in an average risk population in line with a ranking comparable with or higher than CTC, as well as a first-line imaging test after incomplete OC,” investigators wrote.
Disclosure: The study was funded by Medtronic, and several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Cash BD, Fleisher MR, Fern S, et al. Multicentre, prospective, randomised study comparing the diagnostic yield of colon capsule endoscopy versus CT colonography in a screening population (the TOPAZ study). Gut. Published online December 18, 2020. doi:10.1136/gutjnl-2020-322578