Clinicopathological Features and Outcomes of Endoscopic Submucosal Dissection for Early Gastric Lymphoepithelioma-like Carcinoma.

Background/objectives: The curability of endoscopic submucosal dissection (ESD) for early gastric lymphoepithelioma-like carcinoma (LELC) remains unclear, as this rare histological subtype is not well represented in current guidelines. We aimed to evaluate the clinicopathological features and outcomes of early gastric LELC following ESD.

Methods: We retrospectively compared 51 patients with early gastric LELC and 8243 patients with well- or moderately differentiated (WD or MD) tubular adenocarcinoma who underwent ESD.

Results: LELC was more frequently located in the proximal stomach than WD/MD adenocarcinoma (52.9% vs. 10.3%). The deep submucosal invasion rate was significantly higher in LELC (77.3% vs. 9.5%), whereas the lymphatic invasion rate was comparable between the two groups (5.7% vs. 9.2%). No LELC cases were diagnosed preoperatively using forceps biopsy. Despite the comparable en bloc with R0 and complete resection rates, the curative resection rate of LELC was significantly lower than that of WD/MD adenocarcinoma, primarily due to deep submucosal invasion. Post-ESD bleeding was more frequent in LELC (11.3% vs. 2.7%). During a mean follow-up of 38.1 months, no extra-gastric recurrence was observed in patients who did not undergo additional surgery, and no lymph node metastasis was detected among the 23 patients who underwent gastrectomy. No gastric cancer-specific deaths occurred in the study population during follow-up.

Conclusions: Considering these favorable long-term outcomes despite a low curative resection rate, early gastric LELC fulfilling the conventional curative criteria of current guidelines can be regarded as having been curatively treated by ESD, particularly in patients with high surgical morbidity.