Characteristics of lymph node metastasis in early gastric cancer: a single-center retrospective study

OBJECTIVE: This study aimed to characterize lymph node metastasis(LNM) in early gastric cancer (EGC) to investigate the applicability of EGC treatment options in China, as defined in the Japanese guidelines. METHODS: A single-center retrospective analysis was conducted using data from a high-volume tertiary hospital in Western China between 2007 and 2020 to explore LNM characteristics, risk factors, and prognosis in EGC patients who underwent gastrectomy. RESULTS: The study enrolled 1,140 EGC cases, including 538 intramucosal(M) and 602 submucosal(SM), with 250(21.9%) experiencing LNM. For upper third EGC, lymph node(LN) stations of No.1, No.2, No.3, No.7, No.11, and No.12a showed LNM, of which the metastasis rate of No.3 exceeded 5%. The metastasis rate of No.3 exceeded 10%, and that of No.4 exceeded 5% when the primary lesion was in the middle third of the stomach. For lower third EGC, among which the metastasis rates of No.6 and No.3 exceeded 10% and that of No.4 exceeded 5%. Undifferentiation type, submucosal invasion, lymphatic-vascular invasion, and number of LNs retrieved were independent risk factors for LNM in EGC. The 5-year OS rate of EGC was 95.1% and which for N1, N2, and N3 were 94.1%, 90.2%, and 82.4%, respectively (p = 0.00038). CONCLUSIONS: EGC patients in Western China exhibit a higher risk of LNM, regardless of the tumor's site or the presence of submucosal infiltration. The Nos. 3, 4, and 6 are the most common regional LN stations with higher rates of LNM.