Clinical significance of nm23 expression in resected pathologic-stage I, non-small cell lung cancer

Background. Clinical significance of the status of nm23 gene, originally identified as an antimetastatic gene, in non-small cell lung cancer remains unestablished, whereas many clinical studies have demonstrated that reduced nm23 expression is correlated with tumor progression and poor prognosis in a variety of malignant tumors such as breast carcinoma. Methods. nm23 expression was examined immunohistochemically in a total of 117 patients with completely resected pathologic stage I non-small cell lung cancer. Results. nm23 expression was positive in 73 (62.4%) patients, and there was no correlation between nm23 expression and age, sex, performance status, pathologic T factor, histologic type, or degree of cancer cell differentiation. The 5-year survival rates of nm23-positive and nm23-negative patients were 79.7% and 57.8%, respectively, demonstrating a significantly poorer prognosis in nm23-negative patients (p = 0.013), which was confirmed by a multivariate analysis. nm23 was not correlated with the incidence of apoptosis, proliferative activity, or p53 status. Conclusions. nm23 expression was a significant factor for predicting a favorable prognosis, suggesting antimetastatic potential of the nm23 gene in non-small cell lung cancer.