Purpose To explore whether vasculogenic mimicry (VM) exists in Orbital Rhabdomyosarcoma (ORMS) to elucidate the relationship between the expression of epithelial cell kinase (EphA2) and VM, and the clinical significance.
Methods We collected 32 paraffin-embedded human ORMS samples, with detailed follow-up and clinicopathologic data. CD31/ periodic acid-Schiff (PAS) immunohistochemical andhistochemical double staining were performed to validate the existence of VM in ORMS. Vasculogenic mimicry density (VMD) was counted respectively.
Results VM was observed in 11 of the 32 ORMS patients (34.0%), especially in poorly differentiated ORMS (P=0.01). Patients with VM were recurrence compared with patients without VM (P = 0.021). Immunohistochemical staining index (SI) of EphA2 was compared between the VM and non-VM group. There were positive for EphA2 56% (18/32). The SI of four factors were all higher in the VM group than those of non-VM group (P=0.004). The Kaplan-Meier survival analysis showed that the VM group has shorter life span compared with non-VM group (P = 0.022). There was a positive association between the expression of EphA2 and VM (r=0.53, P=0.006).
Conclutions VM exists in ORMS, it is an unfavorable prognostic indictor for ORMS. Over-expression of EphA2 may induce the formation of VM channels. The combined detection of VM and EphA2 has an important role in predicting the progression and prognosis of ORMS.