Correlation between the expression abnormalities of E-cadherin-β-catenin complex and lymph node metastasis (LNM) in early gastric cancer

Abstract

15105 Background: Therapy for early gastric cancer (GC) varies according to risk of LNM. When the possibility of LNM is very remote, the primary lesion can be resected by the minimally invasive endoscopic surgery only. Therefore, useful parameters predicting LNM are needed. E-cadherin, a component of the cell-cell junctional structure, is known to correlate with GC. In vitro, previous studies elucidated that disorders of cell-cell junction increased the potential of metastasis, and that phosphorylation of β-catenin by c-erbB-2 induced loss of membranous E-cadherin and β-catenin, resulting in junctional structure disorders. Here we evaluated significance of analysis of these molecules in LNM prediction in early GC. Methods: The clinicopathological features and immunohistochemical expressions of E-cadherin, β-catenin, and c-erbB-2 in the primary lesion were studied in 28 patients (LNM +ve group: 14, LNM1 -ve group: 14) selected from 272 patients who underwent radical surgery for early GC between April 2000 to March 2004 at our hospital. All the patients consented to use of their stomach tissues for the clinical study afterwards. Statistical analysis was performed by t-test or χ2 test. Results: The clinicopathological features showed no significant differences between both groups. Loss of the membranous E-cadherin was noticed in 12 (85%) of the 14 LNM +ve patients, and in 8 (57%) of the 14 LNM -ve patients (p=0.209). This result was more remarkable in the intestinal type GC as the corresponding figures were 83% (5 of 6 ) and 16% (1 of 6) (p=0.083), respectively. Loss of the membranous β-catenin also showed a remarkable similar trend in the intestinal type GC, and the corresponding figures were 100% (6 of 6) and 50% (3 of 6) (p=0.182), respectively. Two patients showed over-expression of c-erbB2 and nuclear accumulation of β-catenin, and both had intestinal type GC with LNM. Conclusions: These results suggested that the same molecular signal pathway - as in vitro - including E-cadherin, β-catenin, and c-erbB2 induced LNM in early GC (intestinal type). We concluded that analysis of the expressions of these molecules is useful for not only LNM prediction but also determination of the therapeutic modality especially in intestinal type early GC. No significant financial relationships to disclose.