Abstract: Objective To investigate the effects of platelet infusion on serum matrix metalloproteinase 9(MMP-9), Matrix metalloproteinase 2(MMP-2) and vascular endothelial growth factor(VEGF) levels in patients with advanced lung cancer, and to observe whether the platelets injected can promote the metastasis of advanced lung cancer.
Methods A total of 89 patients with advanced lung cancer who received platelet infusion were selected. They are divided into the effective group and the ineffective group according to whether platelet infusion was effective(CCI>7.5 was effective). The serum levels of MMP-9, MMP-2 and VEGF in the two groups were compared before and after platelet infusion(12-24 h).
Results The effective rate of platelet infusion was 80.90%(72/89).After platelet infusion, the serum levels of MMP-9, MMP-2 and VEGF in the effective group were significantly higher than those in the ineffective group, and the serum levels of MMP-9, MMP-2 and VEGF in the effective group were higher than those before platelet infusion, and all the differences were statistically significant(P＜0.05).
Conclusion The effective infusion of platelets can increase the levels of serum MMP-9, MMP-2, and VEGF in patients with advanced lung cancer, which may promote the invasion and metastasis of lung cancer, suggesting that platelets should be injected into lung cancer patients more carefully.

Key words: lung tumor, platelet transfusion, tumor invasion