Prognostic significance of metastasis-suppressor gene NM23 in gastric carcinoma

Aim: Metastasis is critical in the prognosis of gastric cancer patients and in deciding on treatment strategies. Therefore, studies have concentrated on metastasis suppressor genes. This study aimed to identify the characteristics of NM23 expression in gastric cancer and to investigate its anti-metastatic and prognostic significance. Methods: Ninety patients who underwent surgery for gastric cancer between January 1, 2009 and January 1, 2010 were included in this study. Immunohistochemical staining was applied to specimen sections. The results of the immunohistochemical staining were evaluated with the normal gastric mucosa adjacent to the tumor. The degree of NM23 staining of tumor cell compared to the normal tissue was evaluated in two groups of “negative-weak staining” and “strong staining”. Both groups were analyzed for lymph node metastasis, vascular invasion, perineural invasion, degree of tumor differentiation, tumor stage and distant metastasis. Results: Among 58 patients with lymph node metastasis, 70.7% showed negative-weak staining and 29.3% showed strong staining. Among 32 patients with no lymph node metastasis, 40.6% had negative-weak staining and 59.4% had strong staining. Decrease in NM23 expression was shown to cause an increase in lymph node metastasis (P=0.01). Furthermore, while there was no statistical significance, the rates of distant metastasis, degree of poor differentiation, tumors in stage III and stage IV were apparently higher in the negative-weak staining group. These results were in line with the anti-metastatic property of NM23.  Conclusion: This study showed that NM23 expression had anti-metastatic properties for lymph node metastasis in gastric cancer patients .