A Comparison by Meta-Analysis of Papillary Early Gastric Carcinoma to Its Tubular Counterpart for the Risk of Lymph Node Metastasis and Submucosal Invasion.

Background and Aim: At present, the decision to perform endoscopic resection for treating either papillary early gastric cancer (EGC) or tubular EGC is made according to identical criteria. However, there is controversy in the literature whether the risk of lymph node metastasis (LNM) and submucosal invasion for both disease modalities is equal, and this prompts investigation to clarify this issue. Methods: The PubMed and Web of Science databases were searched for relevant studies published up to January 2017. Data were extracted, and the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using a random-effects or a fixed-effects model, according to heterogeneity. Results: A total of 13 studies were included in this analysis. Papillary EGC had a significantly higher LNM risk (OR, 1.97; 95% CI, 1.38-2.82) and submucosal invasion risk (OR, 1.44; 95% CI, 1.08-1.93), compared with tubular EGC. Stratified by geographic location, a significantly increased risk of LNM (OR, 2.28; 95% CI, 1.57-3.30) and submucosal invasion (OR, 1.52; 95% CI, 1.13-2.04) associated with papillary EGC was found in Asian studies. In addition, papillary EGC exhibited significantly more frequent elevated/flat growth patterns (OR, 7.54, 95% CI, 4.76-11.96). Conclusions: Our study identifies an increased risk for submucosal invasion and LNM in papillary EGC compared with tubular EGC, indicating that papillary EGC requires more careful clinical management compared with tubular EGC.