Abstract: Objective To study the relationship between the change of expression levels of vascular endothelial growth factors（VEGF）and matrix metalloproteinase-9（MMP-9）of advanced breast cancer patients before and after chemotherapy and the chemotherapy response. Methods Sixty-five advanced breast cancer patients in Jiangsu Cancer Hospital from December 1 2009 to December 1 2014 were enrolled in this study. All the patients were infused with two agents chemotherapy， in which 39 were with platinumbased regimen and 26 received nonplatinumbased regimen. Serum samples were collected from the 65 patients respectively before chemotherapy and after 2 cycles chemotherapy to determine the expression levels of VEGF and MMP-9. The expression levels of VEGF and MMP-9 were compared before and after chemotherapy， between platinum-based regimen and non-platinum-based regimen as well as between different efficacies. Meanwhile the median time to progress（TTP） of different expression of VEGF and MMP-9 were evaluated after chemotherapy.
Results The mean value of serum VEGF and MMP-9 were 596.5 pg／ml and 686.5 ng／ml before chemotherapy， higher than 215.0 pg／ml and 500.4 ng／ml after chemotherapy（P＜0.05）. The expression level of VEGF of 56 patients with clinical benefit before and after chemotherapy was 678.1 pg／ml and 232.0 pg／ml（P.0.05）， while the expression level of MMP-9 was 679.3 ng／ml and 450.6 ng／ml（P＜0.05）. Those indexes in 9 patients with disease progression had no differences before and after chemotherapy （P＞0.05）. In 39 patients with platinum-based chemotherapy， the mean value of MMP-9 after chemotherapy were 451.7 ng／ml， lower than 742.6 ng／ml before chemotherapy（P＜0.05）. The median TTP of 30 patients with decreased level of MMP-9（5.0 months）was superior to the 25 patients with increased level of MMP-9（3.0 months） with significant difference （P＜0.05）； whereas there was no significant difference between patients with the decreased and increased level of VEGF（P＞0.05）. Conclusion The decline of serum VEGF and MMP-9 expression levels may be a index of effective chemotherapy in advanced breast cancer.