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 mutL homolog 1, p53, epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) were included. The chi(2) 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.