Endoscopic submucosal dissection of papillary adenocarcinoma of stomach; protocol for a systematic review and meta-analysis

BACKGROUND: Endoscopic submucosal dissection (ESD) is a primary treatment for the early gastric cancer (EGC) who has a negligible risk of lymph node metastasis. Papillary adenocarcinoma (PAC) of stomach is a rare histologic variant of gastric cancer and categorized into EGC with differentiated-histology. However, aggressive features such as higher rate of lymphovascular invasion (LVI) or submucosal invasion have been reported, whereas comparable lymph node metastasis (LNM) rate to the lesions meeting the current ESD criteria also has been reported. This study aimed to evaluate the feasibility of ESD for EGC with PAC. METHODS: We will search the core databases (MEDLINE (through PubMed), the Cochrane Library, and Embase) from their inception to December 2018 by 2 independent evaluators. The P.I.C.O. is as follows; Patients: who have EGC with PAC, Intervention: ESD or surgery, Comparison: none, Outcome: at least one among the rate of complete resection, curative resection, en bloc resection, recurrence, procedure-related adverse event, LVI or LNM that enabled an evaluation of the feasibility of ESD. All types of study design with full text will be sought and included. The risk of bias will be assessed using the ROBINS-I tool. Descriptive data synthesis is planned, and quantitative synthesis will be used if the included studies are sufficiently homogenous. Publication bias will be assessed with quantitative analyses if more than 10 articles are enrolled. RESULTS: The results will provide evidence for efficacy and safety of ESD for EGC with PAC. CONCLUSION: This study will provide evidence of ESD for EGC with PAC.