BACKGROUND: Metastasis-Associated in Colon Cancer-1(MACC1) was first identified as a transcriptional activator of the HGF/MET pathway. Deregulation of HGF/MET signaling is reported as a prognostic marker for tumorigenesis, early stage invasion, and metastasis which is associated with poor clinical outcome in breast cancer patients. The aim of the present study was to further investigate the prognostic or predictive value of MACC1 expression in breast cancer. MATERIALS AND METHODS: We analyzed the MACC1 expression in 105 primary breast cancer samples by Western-Blot analysis and immunohistochemistry. RESULTS: A significant correlation of high MACC1 expression with shorter disease-free survival was found within the group of lymph-node-negative patients. Additionally, an association of high MACC1 expression and shorter disease-free survival was observed within estrogen receptor positive tumors and patients without adjuvant chemotherapy. CONCLUSION: Our results support a biologic role and potentially open the perspective for the use of MACC1 as a prognostic marker for treatment decision in breast cancer patients.