Endoscopic submucosal dissection versus surgery for undifferentiated-type early gastric cancer: A meta-analysis.

111 Background: It is still controversial to treat undifferentiated early gastric cancer by endoscopic submucosal dissection (ESD). Therefore, we aimed to perform a meta-analysis to investigate long-term outcomes of ESD and surgery for undifferentiated early gastric cancer. Methods: PubMed, Cochran Library, and EMBASE were used to search for relevant researches comparing endoscopic submucosal dissection and surgery for undifferentiated early gastric cancer. The methodological quality of the included publications was evaluated using the Risk of Bias Assessment tool for Non-randomized Studies. The overall survival rate, recurrence rate, adverse event rate, and complete resection rate were explored, and the odds ratio (OR) and 95% confidence interval (CI) were estimated. Results: This meta-analysis enrolled five studies, with 376 and 1148 participants undergoing ESD and surgery, respectively. Overall survival rate did not show significant difference between ESD and surgery group (OR 0.57, 95% CI 0.18 – 1.83, P = 0.34). However, ESD was associated with higher recurrence rate (OR 11.57, 95% CI 5.07 – 26.39, P < 0.001) and lower complete resection rate (OR 0.03, 95% CI 0.01 – 0.11, P < 0.001). Adverse event rate was similar between two groups (OR 0.95, 95% CI 0.46 – 1.96, P = 0.88). Conclusions: Despite higher recurrence rate and lower complete resection rate, ESD demonstrated similar overall survival rate and adverse event rate in the treatment of undifferentiated early gastric cancer compared to surgery.