The significance of nm23 protein expression in human gastric carcinomas.

The clinical significance of nm23 protein (nm23) expression was studied in tissue samples from 110 patients with primary gastric cancer by immunohistochemical staining with the anti-nm23 antibody. Primary carcinomas with either lymph node involvement or liver metastasis expressed significantly reduced levels of nm23 compared to those without metastasis. This relationship was clearer in the more differentiated adenocarcinomas than in the poorly differentiated adenocarcinomas. However, there was no correlation between nm23 expression and depth of invasion, quantity of stroma, infiltrating growth pattern, or macroscopic type. The cumulative 5-year survival rates based on nm23 immunoreactivity within the primary tumor were significantly higher in the nonreduced expression group (72%) than in the reduced expression group (45%). A multivariate analysis revealed that nm23 expression levels influence the outcome of patients as strongly as depth of invasion and more strongly than the other clinicopathological factors. These results suggest that the degree of nm23 expression is closely related to the metastatic potential of gastric carcinoma cells and can be used as a prognostic indicator independent of the clinicopathological features.