Their results showed Luminal B breast cancer patients with positive axillary lymph nodes had a poorer 10-year recurrence free survival rate and a poorer overall survival rate when compared with Luminal A breast cancer patients. Furthermore, two meta-analyses showed that Ki-67 is an important factor affecting the recurrence of early breast cancer and the survival of breast cancer patients. The cut-off level for Ki-67 positive staining has varied from 5% to 30%, which complicates the comparison of the findings. The prognostic value of Ki-67 has been associated with poorer BAY 73-4506 abmole prognosis in breast cancer patients with negative axillary lymph nodes in most studies. However, racial differences and ethnic origins appear to affect the frequency of high Ki-67 expression in breast cancer. In Southern China, approximately 50% of breast cancer patients have 1 or more positive nodes at diagnosis. Compared to studies of breast cancer patients with no positive nodes, the prognostic value of Ki-67 in breast cancer patients with positive axillary lymph nodes was investigated in fewer studies and was more variable. Some studies observed a significant unfavorable prognostic value of Ki-67. Matsubara et al found that high Ki-67 expression in Japanese patients with breast cancer and positive axillary lymph nodes was an unfavorable prognostic factor for disease free survival and overall survival. Weisner et al observed a significantly higher Ki-67 overexpression in breast cancer tissues from Caucasian patients with 1-3 positive axillary nodes but not those with 4 or more positive nodes. The role and the prognostic value of Ki-67 in breast cancer patients with positive axillary nodes are unknown. In this retrospective study, the prognostic value of the Ki-67 marker was evaluated in Chinese patients with breast cancer and with one or more positive axillary lymph nodes. Approximately half of breast cancer patients in China have one or more positive lymph nodes and these patients show significantly lower rates of disease-free survival and overall survival than breast cancer patients with only negative nodes. Despite post-operative adjuvant therapy based on the pathology, status of axillary lymph nodes, tumor size and status of hormone receptors in breast cancer patients, more than 15% of patients develop incurable disease. Identification of these patients with non-responsive breast cancer so their therapy can be individualized is a hot topic in breast cancer research. Biomarker profiles can provide prognostic value for probability of therapeutic responses, especially to targeted therapies. Ki-67 is a marker reflecting the proliferative capability of cancer cells and is being widely investigated in breast cancer studies. Our results indicate that the prognostic value of Ki-67 is influenced by the number of positive lymph nodes of the breast cancer patients.