Expression of nucleoside diphosphate kinase/nm23 gene product in human pancreatic cancer: an association with lymph node metastasis and tumor invasion

The expression of nucleoside diphosphate (NDP) kinase/nm23 has been reported to be inversely related to metastasizing potential of experimental cells and human breast cancer. In the present study, levels of NDP kinase/nm23 gene product in curatively resected human pancreatic adenocarcinomas were examined immunohistochemically using anti-NDP kinase antibody. Immunoreactivity for NDP kinase varied between tumors. Of 31 pancreatic tumors examined, 17 (55%; positive staining group) showed strong immunoreactivity for the NDP kinase, while 14 (45%; negative staining group) showed low or no immunoreactivity. Positive staining was associated with higher incidence of lymph node metastasis (13/17; 77%) and perineural invasion (13/17; 77%) than negative staining (5/14, 36%, P < 0.03; 4/14, 29%, P < 0.01, respectively). Positive staining was also associated with shorter overall survival and relapse-free survival than negative staining (P < 0.01, P < 0.01, respectively). No significant difference in age, sex, size, location of tumor, serum carcinoembryonic antigen (CEA) level, or histological type was found between the two groups. These results showed that, in contrast to the reports on breast cancer, NDP kinase/nm23 expression in human pancreatic cancer is positively associated with lymph node metastasis or perineural invasion and with poor prognosis. These, together with other previous reports, suggest that NDP kinase may play an important role in cancer progression or aggressiveness by altering its expression in a tissue-specific manner.