Objective: To investigate the expression and clinical significance of matrix metalloproteinase-9 and its complex in the urine of the patient with breast cancer.
Methods: Using substract gel electrophoresis and western-blot analysis, expressions of MMP-9 and MMP-9/NGAL complex in breast cancer (n = 97), breast benign (n = 41) and normal (n = 60) were observed.
Results: There MMP-9 and MMP-9/NGAL complex expressions were 76.29% and 64.95% in breast cancer, 46.34% and 43.90% in breast benign, and 23.33% in normal respectively. The MMP-9 and MMP-9/NGAL complex expressions were higher in breast cancer than those in breast benign and in normal (chi(2) = 7.456, P < 0.01). MMP-9 and MMP-9/NGAL complex expressions in urine of breast cancer had not any relationship with tumor size, TNM stage, patient age, menopause status as well as ER status, but was correlated to lymphatic node status (chi(2) = 5.206, P < 0.05).
Conclusions: MMP-9 and MMP-9/NGAL complex expressions in urine are significant in estimating lymphatic node metastasis in breast cancer and a valuable early prognostic factors and screening in breast cancer.