Back-to-back colon capsule endoscopy and optical colonoscopy in colorectal cancer screening individuals

Aim: To determine the polyp detection rate and per-patient sensitivity for polyps >9 mm of colon capsule endoscopy (CCE) compared with colonoscopy as well as the diagnostic accuracy of CCE.

Method: Individuals who had positive immunochemical faecal occult blood test during screening had investigator blinded colon capsule endoscopy and colonoscopy. Participants underwent repeat endoscopy if significant lesions detected by colon capsule endoscopy were considered to have been missed by colonoscopy.

Results: There were 253 participants. The polyp detection rate was significantly higher in colon capsule endoscopy compared with colonoscopy (P=0.02). The per-patient sensitivity for >9mm polyps for CCE and colonoscopy was 87% (95%CI: 83%-91%) and 88% (95% CI: 84-92) respectively. In participants with complete colon capsule endoscopy and colonoscopy examinations (N=126), per-patient sensitivity of >9 mm polyps in colon capsule endoscopy (97%; 95% CI: 94-100) was superior to colonoscopy (89%; 95% CI: 84-94). A complete capsule endoscopy examination (N=134) could detect patients with intermediate or greater risk (according to the European guidelines) with an accuracy, sensitivity, specificity and positivity rate of 79%, 93%, 69% and 58% respectively, using a cut-off of at least one polyp >10 mm or more than two polyps.

Conclusion: Colon capsule endoscopy is superior to colonoscopy in polyp detection rate and per-patient sensitivity to >9 mm polyps, but only in complete CCE examinations. The rate of incomplete colon capsule endoscopy examinations must be improved.