Mechanism of vasculogenic mimicry and its clinicopathologic significance in gastric adenocarcinoma

Abstract

Objective:To explore whether vasculogenic mimicry (VM) exists in gastric adenocarcinoma (GAC) and to investigate the clinicopathologic significance of VM in GAC.Methods:We tended to illuminate the mechanism of VM by performing immunohistochemical staining of MMP-2,MMP-9 and Cathepsin D.A total of 173 GAC samples with detailed follow -up data were collected.CD31/ periodic acid-Schiff (PAS) double staining and CK818 immunohistochemical staining were performed to validate the existence of VM in GAC.The values of MVD (microvascular density) and VMD (vasculogenic mimicry density) were counted respectively.Immunohistochemical staining of MMP-2,MMP-9 and Cathepsin D was performed for all samples.Results:VM was observed in 40 of the 173 GAC samples,especially in poorly differentiated GAC (P=0.014).Patients with VM were prone to hematogenous metastasis and distant recurrence compared with those without VM (P=0.020,0.029).Higher VMD count was also associated with hematogenous metastasis (P=0.003).There was not significant difference in MVD count between VM-positive and VM-negative groups (F=1.596,P=0.482).The Kaplan-Meier survival analysis showed that the survival duration of the VM-positive group was significantly shorter than that of VM-negative group (P=0.022).Cox proportional hazards model indicated that the VM and TNM stage were independent predictors for poor prognosis of GAC (P=0.039 and 0.004).The immunohistochemical expression of MMP-2,MMP-9 and Cathepsin D was higher in VM-positive group than in VM-negative group (P0.05).Conclusion:VM exists in GAC,especially in poorly differentiated GAC.VM is an unfavorable prognostic indicator for GAC.MMP-2,MMP-9 and Cathepsin D might involve the formation of VM in GAC.