Re-evaluation of the role of endoscopic submucosal dissection in the treatment of early gastric cancer based on additional gastrectomy results.

Endoscopic submucosal dissection (ESD) plays a pivotal role in treating early gastric cancer (EGC). Some patients require additional gastrectomy because of non-curative ESD. This study aimed to analyze the clinical factors associated with non-curative ESD and to re-evaluate the role of ESD according to its indication criteria. Altogether, 134 patients who had undergone additional gastrectomy with lymphadenectomy for non-curative ESD based on the pathological results of ESD specimens were included. Their data including pre-ESD diagnosis, reasons for requesting additional gastrectomy, and surgical outcomes were analyzed retrospectively. Of the 134 patients with EGC in the final pathology of ESD specimens, 56 underwent staging ESD for a diagnostic approach, of whom 28 were diagnosed with atypical glands and 28 with high-grade dysplasia (HGD) prior to ESD. The remaining 78 patients of the 134 were identified to have EGC and received ESD for therapy. Based on the pathological results of ESD specimens, additional gastrectomy was commissioned with non-curative ESD because of one or more causes such as deep submucosal invasion, lymphatic invasion, positive vertical margin, undifferentiated histology, positive lateral margin, and venous invasion. Regarding surgical specimens, 13 patients had lymph node metastasis (LNM) and 9 had local residual tumor; one of them had both LNM and a local residual tumor. In patients with atypical glands, 4 had LNM and 3 had a local residual tumor; one of them had both LNM and a local residual tumor, and then died of multiple organ metastasis. In patients with HGD, 4 had LNM and 1 had a local residual tumor. Additionally, 4 patients who were absolutely indicated for ESD had LNM, of whom 2 had atypical glands, and the other 2 had HGD. Similarly, in 6 patients with a local residual tumor absolutely indicated for ESD, 2 had atypical glands and 1 had HGD. Positive vertical margin, lymphatic invasion, and deep submucosal invasion were identified as independent risk factors for LNM. ESD may play diagnostic and therapeutic roles in determining the optimal treatment of EGC when the diagnosis is equivocal or insufficient in endoscopic assessments for gastric cancer screening.