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.