Risk factors for lymph node metastasis and survival: Toward better endoscopic selection in ulcerative versus nonulcerative early gastric cancer.

[BACKGROUND] Lymph node metastasis (LNM) is a major determinant of patient outcomes in early gastric cancer (EGC) patients. This study aimed to identify risk factors for LNM and compare outcomes between patients with ulcerative EGC (UEGC) and with nonulcerative EGC (NUEGC).

[METHODS] We retrospectively analyzed the data of 1262 patients with pathologically confirmed EGC who underwent curative gastrectomy. The risk factors for LNM and overall survival (OS) were assessed. OS was estimated with Kaplan‒Meier analysis, and prognostic factors were identified via Cox regression analysis.

[RESULTS] LNM was significantly more common in the UEGC group (16.6 %) than in the NUEGC group (11.6 %) (P = 0.013). According to the multivariable analysis, lymphovascular invasion (LVI) (OR = 17.609, P < 0.001 for NUEGC; OR = 14.587, P < 0.001 for UEGC), superficial submucosal (SM1) invasion (OR = 2.622, P = 0.045 for NUEGC; OR = 2.276, P = 0.022 for UEGC), and deep submucosal (SM2) invasion (OR = 3.276, P = 0.004 for NUEGC; OR = 3.132, P = 0.001 for UEGC) were independent predictors of LNM in both groups, whereas a tumor size>30 mm (OR = 2.644, P = 0.009) was a significant factor only for NUEGC patients. The 5-year OS rate was 89.9 % in the NUEGC group and 87.2 % in the UEGC group (P = 0.028, log-rank test). LNM was an independent predictor of OS in both subtypes of EGC, whereas elevated carcinoembryonic antigen (CEA) levels and SM2 invasion were significant predictors only for UEGC patients.

[CONCLUSION] Compared with NUEGC, UEGC presents more aggressive pathological features and is characterized by a significantly higher rate of LNM and worse long-term patient survival, while undifferentiated UEGC <2 cm potentially supports ESD expansion.