Expression of nm23-H1 gene product in nasopharyngeal carcinoma and its clinical significance

Objective: The nm23 gene is one of the tumor metastatic suppressor genes. The expression of nm23-H1 has been reported to be inversely associated with metastatic potentiality in a number of human carcinomas, including breast, colorectal, gastric, hepatocellular and gallbladder carcinomas. In this study, the immunohisto-chemical staining of nm23-H1 protein in human naso-pharyngeal carcinoma (NPC) was examined, and the relationship between nm23-H1 and both metastasis and prognosis of patients with NPC was also investigated. Methods: Routine LSAB immunohistochemistry with the nm23-H1 monoclonal murine antibody was employed to study the expression of nm23-H1 protein in 95 paraffin-embedded specimens of NPC treated at our hospital. The clinical pathologic data and results of follow-up were also retrieved. Comparisons between patients with and without expression of nm23-H1 protein with respect to metastasis, loco-regional recurrence and survival were performed using Log rank test. Multivariate prognostic analyses were performed by using Cox’s regression model. Results: Nm23-H1 negative expressive tumors were associated with a higher incidence of lymph-node metastasis (86.7%) than those of nm23-H1 positive (48.6%,P<0.01). Nm23-Hl negative expressive tumors were associated with a high incidence of recurrence and distant metastasis after radiotherapy (P<0.05). A significant association was found between expression of nm23-H1 and prognosis (P<0.01). The expression of nm23-H1 indicated favorable prognosis. Conclusion: It was suggested that nm23-H1 negative expression was significantly associated with lymph-node metastasis, recurrence and distant metastasis. Nm23-H1 may have value for predicting the prognosis of NPC.