Estimation of Invasion Depth of Early Colorectal Cancer Using Endoscopic Ultrasonography and Magnifying Chromoendoscopy: A Meta-Analysis.

Introduction: Magnifying chromoendoscopy (MCE) and endoscopic ultrasonography (EUS) are often used as diagnostic tools to estimate the depth of invasion in early colorectal cancers (CRCs). The aim of this study was to compare MCE with EUS in distinguishing between slight submucosal invasion (invasion depth <1,000 μm) and massively submucosal invasion in patients with early CRCs, since slight submucosal invasion is currently considered as an indication for endoscopic resection and submucosal cancer with massively submucosal invasion should be surgically treated due to an increased risk of lymph node metastasis.

Methods: For this meta-analysis, relevant studies were identified from PubMed, Embase, and the Cochrane Library databases between the time of the establishment and April 2023. Data on the yield of tumors were extracted, pooled, and analyzed by STATA15.0 software. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio in differentiating massive submucosal invasion from slight submucosal invasion were calculated for both diagnostic modalities.

Results: Twenty-six studies involving 12,586 lesions were included: sixteen were studies on MCE and 7 were studies on EUS and 3 were studies on both MCE and EUS. The pooled sensitivity of MCE was 0.78 (95% CI 0.72-0.83), the specificity was 0.95 (0.95% CI 0.91-0.97), the positive likelihood ratio was 15.4 (0.95% CI 8.7-27.4), and the negative likelihood ratio was 0.23 (0.95% CI 0.18-0.30). The pooled sensitivity of EUS was 0.88 (95% CI 0.81-0.93), the specificity was 0.87 (0.95% CI 0.80-0.91), the positive likelihood ratio was 6.7 (0.95% CI 4.4-10.3), and the negative likelihood ratio was 0.13 (0.95% CI 0.08-0.23).

Conclusion: The sensitivity tended to be higher in EUS than MCE for early CRCs with massively submucosal invasion, whereas the specificity was significantly lower in EUS than in MCE.