Real-World Evidence for Expanding the Criteria for Endoscopic Resection in Submucosal Gastric Cancer: The Role of...

The current expanded criteria for endoscopic resection (ER) of early gastric cancer (EGC) include a non-negligible risk of lymph node metastasis (LNM) in submucosal (SM) disease. We had previously proposed revised criteria incorporating the SM invasion width to better stratify LNM risk. In the present study, we aimed to validate whether these revised criteria improved the identification of truly node-negative, differentiated-type pT1b EGC.

This multicenter retrospective study included 712 patients with differentiated-type SM invasive EGC who underwent gastrectomy at 2 tertiary centers between 2016 and 2023. The SM invasion depth and width were re-evaluated, and the diagnostic performance of the conventional, expanded, and revised criteria (tumor size ≤3 cm, SM depth ≤1,000 µm, SM width ≤4 mm, and no lymphovascular/perineural invasion) for predicting LNM was compared.

LNM was identified in 16.9% of the patients. An SM invasion width >4 mm was a strong independent predictor of LNM (P<0.001) and demonstrated superior discriminatory ability (area under the receiver operating characteristic curve [AUC], 0.79) in comparison with SM depth (AUC, 0.68) and tumor size (AUC, 0.59). Although the conventional criteria classified 54 cases as curative, the revised criteria classified 83 cases as curative, and no LNM events were observed in both sets of cases. Thus, the revised criteria expanded the potential candidate pool for curative ER by approximately 54% without compromising nodal safety.

SM invasion width can be a significant independent predictor of LNM. The revised criteria, which incorporated SM width, safely expanded the indications for curative ER in patients with differentiated-type SM gastric cancer.