Risks and benefits of additional surgery for early gastric cancer in the upper third of the stomach meeting non-curative resection criteria after endoscopic submucosal dissection.

BACKGROUND: Additional surgery is recommended after non-curative endoscopic submucosal dissection for early gastric cancer. However, it is not easy to recommend for tumors located in the upper third of the stomach, because it would be a total or proximal gastrectomy. This study aimed to evaluate the actual risks and benefits of additional gastrectomy for upper third tumors. METHODS: We reviewed the clinicopathological data of patients who underwent total or proximal gastrectomy for early gastric cancer in the upper third of the stomach between March 2002 and January 2021. The incidence of lymph node metastasis and postoperative complications were calculated, and risk factors for lymph node metastasis were identified using logistic regression analysis. Survival rates were analyzed using the Kaplan-Meier method and log-rank test. RESULTS: A total of 523 patients underwent total or proximal gastrectomy for early gastric cancer; 379 of them had tumors meeting the non-curative resection criteria for endoscopic submucosal dissection. The overall lymph node metastasis rate was 9.5%, and lymphovascular invasion was the only significant risk factor for lymph node metastasis (p < 0.001). The most common sites of lymph node metastasis were stations 1, 3, and 7, with their rates being 3.2%, 3.7%, and 3.2%, respectively. Overall and severe (Clavien-Dindo grade III or higher) postoperative complication rates were 21.1% and 14.0%, respectively, while postoperative mortality was 0.5% (2/379). The 5-year overall survival rates for patients with and without lymph node metastasis were 96.1% and 81.1%, respectively (p = 0.076). CONCLUSIONS: Before planning an additional gastrectomy after non-curative endoscopic resection for the upper third tumor, we should consider both the benefit of the 9.5% curability for lymph node metastasis and the risks of the 21% postoperative complications and 0.5% mortality.