Prognostic implication of nm23-H1 expression in colorectal carcinomas

Aims: Expression of nm23 has been identified as a potential metastatic suppressor. In this study, nm23-H1 expression, clinicopathological parameters and influences on clinical outcomes were investigated in colorectal carcinoma patients. Methods: Immunostaining was performed on 185 colorectal carcinomas using a polyclonal anti-nm23-H1 antibody. Results: The nm23-H1 immunoreactivity was weak in 31 (17%), moderate in 48 (26%) and strong in 106 (57%) cases. The well differentiated adenocarcinomas showed significantly strong staining for nm23-H1 compared with the moderately and poorly differentiated adenocarcinomas (chi(2) test, P < 0.001). Advanced tumour stages were associated with reduced nm23-H1 expression (P < 0.001). There was an inverse correlation with angiolymphatic invasion, nodal metastasis and liver metastasis (univariate logistic regression analysis, P < 0.001). In univariate analysis, patients with reduced expression of nm23-H1 had significantly shorter overall and disease-free survival than the strong expression group (log-rank test for trend, P=0.002 and P=0.003, respectively). Conclusions: Our results indicated that reduced nm23-H1 expression showed poor prognosis in colorectal carcinomas. As a result, nm23-H1 expression might be a useful marker to predict outcome while planning treatment.