More Is Not Always Better: A Multicenter Study in Lymphadenectomy During Gastrectomy for Gastric Neuroendocrine Neoplasms

Background and Objective: Few reports address the impact of surgery on the prognosis of rare and heterogeneous gastric neuroendocrine neoplasms (G-NENs). This study analyzed the influence of surgical treatments on prognosis to provide a personalized surgical treatment strategy for G-NEN patients. Methods: The clinicopathological data of 1126 G-NEN patients from 28 Chinese hospitals were analyzed. Cox regression analyses were used to analyze the prognostic factors affecting survival and recurrence, respectively. Results: Cox analysis revealed that in stage I-II but not stage III gastric neuroendocrine carcinoma/mixed adenoneuroendocrine carcinoma (NEC/MANEC) patients, Extended lymph node dissection (ELND) was an independent protective factor for OS and DFS (p 0.05). Furthermore, among patients with stage III disease, the incidence of complications after ELND was significantly greater than that after LLND (28.4% vs. 12.1%, p < 0.001), especially severe complications (Clavien-Dindo grade III-V). Conclusion: ELND may lead to enhanced long-term survival for stage I and II but not stage III NEC/MANEC patients. Our results in multicenter patients do not support the routine use of ELND in stage III NEC/MANEC patients. Funding Statement: This work was supported by National natural science foundation of China (No.81871899); Scientific and technological innovation joint capital projects of Fujian Province (2016Y9031, 2017Y9011); Construction Project of Fujian Province Minimally Invasive Medical Center (No. [2017]171); The second batch of special support funds for Fujian Province innovation and entrepreneurship talents (2016B013). China scholarship council (201908350095). National natural science foundation of China (No.81802312). Declaration of Interests: None of the authors have any competing interests in the manuscript. Ethics Approval Statement: The research proposal was reviewed by the Research Ethics Committee at the university, and all procedures were performed after obtaining written informed consent from the patients following an explanation of the surgical and oncological risks.