Clinicopathologic factors and molecular markers related to lymph node metastasis in early gastric cancer

AIM: To analyze predictive factors for lymph node metastasis in early gastric cancer.METHODS: We analyzed 1104 patients with early gastric cancer(EGC) who underwent a gastrectomy with lymph-node dissection from May 2003 through July 2011. The clinicopathologic factors and molecular markers were assessed as predictors for lymph node metastasis. Molecular markers such as microsatellite instability, human mut L homolog 1, p53, epidermal growth factor receptor(EGFR) and human epidermal growth factor receptor 2(HER2) were included. The χ2 test and logistic regression analysis were used to determine clinicopathologic parameters.RESULTS: Lymph node metastasis was observed in 104(9.4%) of 1104 patients. Among 104 cases of lymph node positive patients, 24 patients(3.8%) were mucosal cancers and 80 patients(16.7%) were submucosal. According to histologic evaluation, the number of lymph node metastasis found was 4(1.7%) for well differentiated tubular adenocarcinoma, 45(11.3%) for moderately differentiated tubular adenocarcinoma, 36(14.8%) for poorly differentiated tubular adenocarcinoma, and 19(8.4%) for signet ring cell carcinoma. Of 690 EGC cases, 77 cases(11.2%) showed EGFR overexpression. HER2 overexpression was present in 110 cases(27.1%) of 406 EGC patients. With multivariate analysis, female gender(OR = 2.281, P = 0.009), presence of lymphovascular invasion(OR = 10.950, P < 0.0001), diameter(≥ 20 mm, OR = 3.173, P = 0.01), and EGFR overexpression(OR = 2.185, P = 0.044) were independent risk factors for lymph node involvement.CONCLUSION: Female gender, tumor size, lymphovascular invasion and EGFR overexpression were predictive risk factors for lymph node metastasis in EGC.