Clinical Significance of Lymph Node Micrometastasis in pN0 Gastric Cancer Patients

Abstract

Purpose. To investigate the relationship between lymph node micrometastasis (LNMM) and clinicopathological factors and to evaluate the prognostic effects of LNMM in pN0 gastric cancer (GC) patients. Methods. One hundred and seventy-two GC patients who received radical gastrectomy with D2 lymph node dissection were enrolled in the present study. 1371 negative lymph nodes from level 2 station confirmed by pathology were examined. The LNMM was diagnosed by telomeric repeat amplification protocol/enzyme-linked immunosorbent assay (TRAP-ELISA). The relationship between clinicopathological factors and LNMM was investigated by multivariate analysis. Survival analysis was performed to evaluate the effects of LNMM on prognosis. Results. LNMM was detected in 423 lymph nodes from 72 patients. The results showed that invasion depth ( $\text{OR}=3.755$ , $P=0.004$ ), TNM staging ( $\text{OR}=3.152$ , $P=0.002$ ), lymphatic invasion ( $\text{OR}=2.178$ , $P=0.009$ ), and tumor differentiation ( $\text{OR}=1.266$ , $P=0.013$ ) were independent risk factors associated with LNMM. Survival analysis showed that patients with LNMM had significantly worse 5-year survival compared with those without LNMM (42% vs. 76.4%, $P<0.05$ ). Multivariate analysis demonstrated that LNMM, tumor size, Lauren type, invasion depth, and lymphatic invasion ( $P<0.05$ ) were independently factors associated with 5-year survival. Conclusions. The findings showed that tumor invasion depth, TNM staging, lymphatic invasion, and tumor differentiation were independent risk factors associated with LNMM occurrence. Moreover, LNMM is a clinically negative prognostic factor in pN0 GC patients.