Comparison of Serum and Plasma MMP-9 Level in Breast Cancer Patients

Matrix metalloproteinase-9 (MMP-9) has recently been reported as a marker gene for several cancers. With respect to our previous results about this gene, in the present study we compare the correlation between the plasma and serum MMP-9 levels and clinical features of breast cancer patients. In this case-control study, 114 breast cancer patients and 87 healthy controls were studded. MMP-9 level was quantitatively measured by zymography and Bio Rad kit (Bio-Rad, Richmond, CA). Plasma MMP-9 level was significantly elevated in breast cancer patients compared with the control subjects (P<0.001). Also there was a correlation between the plasma MMP-9 level and lymph node metastasis (OR, 3.4; P=0.019) and venous invasion (OR, 4.14; P=0.033) of the patients. There was no correlation between the serum MMP-9 level and lymphatic metastasis or venous invasion of the patients. According to our findings, plasma MMP-9 level is a better marker than the serum MMP-9 level for early diagnosis of breast cancer metastasis.