Systematic meta-review: diagnostic accuracy of colon capsule endoscopy for colonic neoplasia with umbrella meta-analysis.

BACKGROUND

Colorectal cancer (CRC) incidence is rising globally, intensifying pressure on endoscopy services. Colon capsule endoscopy (CCE) offers a non-invasive alternative. Despite several systematic reviews showing reasonable polyp detection rates, clinical scepticism remains.

OBJECTIVES

This meta-review and umbrella meta-analysis aim to synthesise evidence on CCE's diagnostic accuracy in polyp and CRC detection, using CT colonography or colonoscopy as the reference standard.

METHODS

We conducted a systematic search of EMBASE, MEDLINE and PubMed for systematic reviews evaluating the diagnostic accuracy of CCE in detecting polyps and CRC. A qualitative thematic review and synthesis were conducted following PRISMA guidelines. A bivariate generalised linear mixed model with random effects was used for pooled diagnostic accuracy estimates, and meta-regression was performed using restricted maximum likelihood estimation.

RESULTS

Nine systematic reviews encompassing 28 unique studies (3472 participants) were included. For polyps of any size, the pooled per-patient sensitivity was 0.79 (95% CI: 0.69-0.86), specificity was 0.77 (95% CI: 0.71-0.82), and the area under the curve (AUC) was 0.81. For polyps ⩾6 mm, sensitivity and specificity were 0.80 and 0.87 (AUC 0.81), and for polyps ⩾10 mm, 0.88 and 0.95 (AUC 0.95), respectively. Second-generation CCE (CCE2) improved diagnostic accuracy across all polyp sizes. For polyps of any size, CCE2 achieved a sensitivity of 0.90, specificity of 0.81 and AUC of 0.82. For polyps ⩾ 6 mm and ⩾10 mm, AUCs were 0.92 and 0.94, respectively. CCE2 showed high sensitivity for detecting any polyp size and polyps ⩾6 mm, with low heterogeneity ( > 0.05,  < 25%). CRC detection sensitivity was 0.96 (95% CI: 0.73-1.00) after excluding cases where the capsule failed to reach the rectum due to battery exhaustion.

CONCLUSION

CCE2 has high diagnostic accuracy for polyps and colorectal cancer detection. While technical challenges persist, CCE2 shows promise as a complementary diagnostic tool to help address the increasing demands for endoscopy services.