NM23 EXPRESSION IN BREAST DUCTAL CARCINOMAS - A 10-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 studi es in breast carcinomas nm23 mRNA and/or protein levels was found to c orrelate inversely with lymph node metastases, and positively with the survival of patients. Using a monoclonal antibody to nm23-H1 protein we have examined the immunohistochemical expression of nm-23 in breast ductal carcinomas of 44 lymph node-negative patients with similar tum or pathologic features. The mean follow-lip period of the patients was 138 months. Thirty two out of 44 tumors (72%) disclosed high immunohi stochemical expression of nm23 protein and 12 (28%) low or negative ex pression. No correlation was observed between nm23 expression and the relapse or death rate of the patients. Similar ly, 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 antimetast atic property of nm23 protein, and indicate that its immunohistochemic al determination has no prognostic significance in the management of n ode-negative breast cancel patients.