Abstract: Objective To study clinical significance of the presence of hMAM mRNA-positive circulating tumor cells in early breast cancer. Methods Peripheral blood was obtained from 50 early breast cancer patients after surgical removal of the primary tumor and before the initiation of adjuvant therapy and analyzed for the presence of hMAM mRNA-positive cells using a nested RT-PCR methodology. All patients were followed up. 20 healthy individuals and 24 patients with breast benign lesions served as controls. Results hMAM mRNA-positive cells were detected in 26.0% of early breast cancer patients, 4.2% of breast benign lesions patients, but not in healthy individuals（P=0.025, P=0.012 respectively). A higher incidence of hMAM mRNA-positive cell detection was associated with overexpression of HER2 receptor on the primary tumor (P=0.037). 8/13 (61.5%) of early breast patients with hMAM mRNA-positive cells relapsed during the follow-up period (P=0.004). Detection of peripheral-blood hMAM mRNA-positive cells was associated with reduced median relapse-free interval（^P=0.002）. Conclusion hMAM mRNA is a specific and suitable molecular marker for the detection of circulating tumor cells in early breast cancer. Detection of peripheral blood hMAM mRNA-positive circulating tumor cells might have an important predictive and prognostic value as a marker of relapse and poor clinical outcome in early breast cancer patients.