[Serum level of MMP-2 in early breast cancer and its correlation with circulating tumor cells].

Objective: To explore the serum levels of MMP-2 in early breast cancer and its clinical significance and correlation with the circulating tumor cells in the patients.
Methods: The serum levels of MMP-2 in breast fibroadenoma (n = 10) and breast cancer (n = 72) were detected by enzyme-linked immunosorbent assay (ELISA). And CK19 mRNA was measured by quantitative reverse transcription-polymerase chain reaction in blood as an index of circulating tumor cells in the patients.
Results: The serum level of MMP-2 in breast cancer was significantly higher than that in breast fibroadenoma (12.24 vs 2.21 µg/L, P = 0.003). Subgroup analysis showed that the serum levels of MMP-2 were higher in HER-2 positive patients than those in HER-2 negative ones (16.77 vs 10.02 µg/L, P = 0.022). CK19 mRNA was found in blood samples from 30 cases of breast cancer and the positive rate was 41.7%. However, it was not detected in the patients with breast fibroadenoma. The mean levels of serum MMP-2 were (15.48 ± 2.02) and (7.16 ± 1.55) µg/L in CK19 positive and negative patients respectively. Significant difference existed between two groups (P = 0.013).
Conclusion: The serum level of MMP-2 in early breast cancer is closely correlated with blood micrometastasis. And its high level may be an important contributing factor for the metastasis of breast cancer.