Paraaortic lymph node micrometastasis and tumor cell microinvolvement in advanced gastric carcinoma

BACKGROUND: Paraaortic lymph node dissection in advanced gastric carcinoma is controversial. The purpose of this study was to investigate the incidence and significance of micrometastasis (MM) or tumor cell microinvolvement (TCM) in these critical lymph nodes.METHODS: A total of 2339 lymph nodes, including 390 paraaortic nodes, obtained from 47 patients with advanced gastric carcinoma were examined immunohistochemically, using cytokeratin antibody.RESULTS: Lymph node metastasis was found in 95 of the 390 paraaortic nodes of 14 patients by routine histological examination. MM or TCM was immunohistochemically detected in 45 of the 295 negative paraaortic lymph nodes from 15 of 33 patients (MM, n = 5; TCM, n = 10). The 5-year-survival rate in the paraaortic node-negative group and cytokeratin-positive group was significantly higher that that of the hematoxilin and eosin-positive group. The total number of lymph node metastases by hematoxylin and eosin staining and the pathological lymph node compartments, by cytokeratin-positive nodes, were prognostic factors by multivariate analysis.CONCLUSIONS: We demonstrated a high rate of MM or TCM in the paraaortic lymph nodes and suggest that such harbored metastases are related to the prognosis of patients with advanced gastric carcinoma. On the basis of this study, a multi-institutional study should be considered.