Endoscopic submucosal dissection for early signet ring cell gastric cancer: A systematic review and meta-analysis

BACKGROUND The use of endoscopic submucosal dissection(ESD) for treating early signet ring cell carcinoma(SRC) is controversial due to the risk of lymph node metastasis.AIM To carry out a meta-analysis to evaluate ESD for therapeutic efficacy and safety in early signet ring cell gastric cancer.METHODS The PubMed, Web of Science, Cochrane Library, and EMBASE databases were used to search for relevant studies evaluating the therapeutic efficacy and safety of ESD in SRC. The rates of recurrence, complete resection, incomplete resection, curative resection, en bloc resection, and adverse events were extracted and analyzed. The methodological quality of the enrolled studies was assessed using the Newcastle-Ottawa Scale. Publication bias was evaluated by the Egger’s test. Institutional review board approval and written consent were not needed for this report.RESULTS This meta-analysis enrolled seven studies with 653 participants undergoing ESD treatment for early SRC. The overall recurrence rate was 0.010 [95% confidence interval(CI): 0.000-0.040, Z = 1.422, P = 0.155]. The total lymph-ovascular invasion rate was 0.038(95%CI: 0.007-0.088, Z = 3.026, P = 0.002). The total en bloc resection rate was estimated at 0.984(95%CI: 0.925-1.000, Z = 19.463, P = 0.000). The total complete and incomplete resection rates were estimated at 0.785(95%CI: 0.596-0.928, Z = 9.789, P = 0.000) and 0.188(95%CI: 0.016-0.468, Z = 2.531, P = 0.011), respectively. The total procedureassociated gastric hemorrhage and perforation rates were estimated at 0.026(95%CI: 0.005-0.061, Z = 3.006 P = 0.003) and 0.004(95%CI: 0.000-0.028, Z = 0.938, P = 0.348), respectively. The curative resection, vertical margin invasion, and lateral margin invasion rates were 72.1%(145/341), 2.3%(8/348), and 34.45%(41/119), respectively.CONCLUSION ESD constitutes a promising therapeutic approach for early undifferentiated SRC gastric cancer. However, further improvements are required for increasing its treatment efficacy and reducing adverse outcomes.