Abstract

The nm23 gene was originally identified by differential hybridization between two murine melanoma cell sublines which have low and high metastatic potential, and located in the chromosome 17q22. This gene has known to be involved in metastasis of several cancers and its down-regulation usually associated with metastasis or disease progression in breast cancer. This study was designed to determine the significance of overexpression of the entimetastatic gene nm23 protein in human breast cancer and to compare it with established clinicopatholoaical prognostic factors such as the tumor size, number of involved lymph nodes, grade of differentiation, and hormone receptor status. 118 surgical specimens, which were obtained from breast cancer between July of 1989 and June of 1993 were used to evaluate nm23 protein expression using immunohistochemical staining. All patients were female. The nm23 protein expression was positive in 74 cases(63%) and was negative in 44 cases(37%). There was a significant inverse relationship between nm23 pratein overexpression and Bloom and Richardson histologic grade(p=0.023). Also overexpression of nm23 was significantly correlated with estrogen and progesterone receptor(p=0.031, 0.001) and with longer disease free survival and overall survival(p=0.0048, 0.0026). In conclusion, nm23 protein overexpression is one of good prognostic indicators independently in human breast cancer.

• Keywords: Breast cancer, Hormone receptors, nm23 protein