Performance of radiographic imaging after incomplete colonoscopy for nonmalignant causes in clinical practice

Double-contrast barium enema is no longer justified as a backup examination for colonoscopy in the population screening program: Population study in an organized fecal immunochemical test-based screening program

BACKGROUND AND AIM

Currently, some countries still acknowledge double-contrast barium enema (DCBE) as a backup confirmatory examination when colonoscopy is not feasible or incomplete in colorectal cancer (CRC) screening programs. This study aims to compare the performance of colonoscopy and DCBE in terms of the risk of incident CRC after negative results in the fecal immunochemical test (FIT)-based Taiwan Colorectal Cancer Screening Program.

METHODS

Subjects who had positive FITs and received confirmatory exams, either colonoscopy or DCBE, without the findings of neoplastic lesions from 2004 to 2013 in the screening program comprised the study cohort. Both the colonoscopy and DCBE subcohorts were followed until the end of 2018 and linked to the Taiwan Cancer Registry to identify incident CRC cases. Multivariate analysis was conducted to compare the risk of incident CRC in both subcohorts after controlling for potential confounders.

RESULTS

A total of 102 761 colonoscopies and 5885 DCBEs were performed after positive FITs without neoplastic findings during the study period. By the end of 2018, 2113 CRCs (2.7 per 1000 person-years) and 368 CRCs (7.6 per 1000 person-years) occurred in the colonoscopy and DCBE subcohorts, respectively. After adjusting for major confounders, DCBE had a significantly higher risk of incident CRC than colonoscopy, with an adjusted HR of 2.81 (95% CI = 2.51-3.14).

CONCLUSIONS

In the FIT screening program, using DCBE as a backup examination was associated with a nearly threefold risk of incident CRC compared with colonoscopy, demonstrating that it is no longer justified as a backup examination for incomplete colonoscopy.

Multicentre, prospective, randomised study comparing the diagnostic yield of colon capsule endoscopy versus CT colonography in a screening population (the TOPAZ study)

OBJECTIVE

Colon capsule endoscopy (CCE) has shown promise for colorectal neoplasia detection compared with optical colonoscopy (OC), but has not been compared with other screening tests in average risk screening patients.

DESIGN

Patients 50 to 75 years of age (African Americans, 45-75 years) were randomised to CCE or CT colonography (CTC) and subsequent blinded OC. The primary endpoint was diagnostic yield of polyps ≥6 mm with CCE or CTC. Secondary endpoints included accuracy for size and histology, examination completeness, number/proportion of subjects with polyps and adenomas ≥6 mm and ≥10 mm, subject satisfaction and safety.

RESULTS

From 320 enrolled subjects, data from 286 (89.4%) were evaluable. The proportion of subjects with any polyp ≥6 mm confirmed by OC was 31.6% for CCE versus 8.6% for CTC (pPr non-inferiority and superiority=0.999). The diagnostic yield of polyps ≥10 mm was 13.5% with CCE versus 6.3% with CTC (pPr non-inferiority=0.9954). The sensitivity and specificity of CCE for polyps ≥6 mm was 79.2% and 96.3% while that of CTC was 26.8% and 98.9%. The sensitivity and specificity of CCE for polyps ≥10 mm was 85.7% and 98.2% compared with 50% and 99.1% for CTC. Both tests were well tolerated/safe.

CONCLUSION

CCE was superior to CTC for detection of polyps ≥6 mm and non-inferior for identification of polyps ≥10 mm. CCE should be considered comparable or superior to CTC as a colorectal neoplasia screening test, although neither test is as effective as OC.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov no: NCT02754661.