Long-Term Outcomes of Mucosal Early Gastric Cancer with Lymphatic Invasion as the Sole Non-Curative Factor After Endoscopic Submucosal Dissection.

BACKGROUND

The clinical significance of lymphatic invasion in mucosal early gastric cancer (EGC) treated with endoscopic submucosal dissection (ESD) remains unclear. We evaluated clinicopathologic features and long-term outcomes in patients with lymphatic invasion as the sole non-curative factor.

METHODS

We retrospectively reviewed 9117 patients who underwent ESD for EGC at Samsung Medical Center between 2001 and 2022. Among patients with mucosal disease and lymphatic invasion as the sole non-curative factor, long-term clinical outcomes were summarized using an outcome flowchart, and characteristics of lymph node-positive cases were analyzed in relation to curative resection criteria.

RESULTS

Among 7444 patients with mucosal EGC treated with ESD, lymphatic invasion was identified in 154 patients (2.1%). Among the 117 patients with lymphatic invasion as the sole non-curative factor, the overall rate of pathologically confirmed or clinically suspected lymph node metastasis (LNM) was 4.3% (5/117). Specifically, LNM was identified in 3.2% (3/95) of patients who underwent additional surgery, and in 9.0% (2/22, including one clinically suspected case) managed with observation alone during a median follow-up of 58.0 months. LNM was observed exclusively in lesions involving the muscularis mucosae or in lesions larger than 2 cm, whereas no LNM occurred in tumors confined to the lamina propria measuring ≤ 2 cm.

CONCLUSIONS

Despite mucosal confinement, lymphatic invasion was associated with a clinically meaningful risk of LNM, whereas no LNM was observed in lesions ≤ 2 cm confined to the lamina propria. For patients with mucosal EGC in whom lymphatic invasion is the sole non-curative factor, careful, individualized decision-making is warranted.