Evaluation of prognostic significance in extracapsular spread of lymph node metastasis in patients with gastric cancer

Background. Extracapsular spread of lymph node metastasis has been shown as a negative prognostic factor in cancers of several other organs. This study was performed to clarify the prognostic significance of extracapsular spread in patients receiving curative resection for gastric cancer. Methods. Extracapsular spread was defined as infiltration of cancer cells beyond the capsule of the metastatic lymph node. Four hundred and two patients who underwent curative gastrectomy were evaluated. Eight Potential prognostic factors, including the International Union Against Cancer (Union International Contra la Cancrum; [UICC]) N stage and nodal status classified by the presence of lymph node metastasis or extracapsular spread, were examined. Results. Three survival curves grouped by nodal status differed significantly, and prognosis of patients with extracapsular spread was significantly worse than for the other groups. Both UICC N stage (P < .001) and nodal status (P < .001) were significant prognostic factors by multivariate analysis. UICC N stages were subcategorized by nodal status, and survival was shown to be significantly worse in patients with extracapsular spread in the UICC N1 group (P = .04). Conclusions. Extracapsular spread was a significant negative prognostic indicator on multivariate analysis, and may be useful in combination with UICC N stage. Extracapsular spread was regarded as an important indicator to refine the nodal staging system in gastric cancer.