Nm23 expression in breast ductal carcinomas : A ten year follow-up study in a uniform group of node-negative breast cancer patients

The nm23 gene was originally identified in murine melanoma cell lines as a putative metastasis suppressor gene. In a limited number of studies in breast carcinomas nm23 mRNA and/or protein levels were found to correlate inversely with lymph node metastases, and positively with the survival of patients. Using a monoclonal antibody to nm23-HI protein we have examined the immunohistochemical expression of nm-23 in breast ductal carcinomas of 44 lymph node-negative patients with similar tumor pathologic features. The mean follow-up period of the patients was 138 months. Thirty two out of 44 tumors (72%) disclosed high immunohistochemical expression of nm23 protein and 12 (28%) low or negative expression. No correlation was observed between nm23 expression and the relapse or death rate of the patients. Similarly, no association was found between nm23 protein levels and estrogen receptor status or p53 protein. Our results do not seem to agree with the proposed antimetastatic property of nm23 protein, and indicate that its immunohistochemical determination has no prognostic significance in the management of node-negative breast cancer patients.