Background: Vascular endothelial growth factor (VEGF) is a multifunctional cytokine involved in angiogenesis as selective mitogen for endothelial cells as well as potent permeability factor. And interleukin-6 (IL-6) is also known to be a
growth
factor of myeloma cells. To relationship between the level of VEGF expression, microvessel count (MVC), IL-6 expression in the bone marrow specimen of multiple myeloma patients and stage, response, survival duration were evaluated in 18 patients
with
multiple myeloma who underwent bone marrow biopsy.
Methods: VEGF expression, MVC and IL-6 expression were assessed by immunohistochemical stain with polyclonal antibody to VEGF, factor Ⅷ related antigen and IL-6 respectively.
Results: VEGF expression was higher in multiple myeloma than that of control (61.4±34.4% vs 19.0±25.9%, P<0.001), and MVC was also higher in multiple myeloma than that of control (11.7±6.1 vs 6.2±3.8, P=0.005). IL-6 was expressed in
66.7% of
multiple myeloma but not in control (P<0.001). Between high VEGF expression group and low VEGF expression group, there were no significant differences in the stage, response or survival. There were no significant differences between hypervascular
group
and hypovascular group. Also IL-6 expression was not a prognostic indicator. After treatment, VEGF expression, MVC and IL-6 expression were decreased in the responder, but these differences were not statistically significant (P=0.23, P=0.07,
P=0.06),
probably due to limited number of cases.
Conclusion: VEGF, angiogenesis and IL-6 can play a role in the pathogenesis of multiple myeloma. But we cannot confirm the prognostic role of those parameters. Further study with more cases in longer duration as well as prospective study
would be
necessary for the establishment of relationship between VEGF expression, neovascularization, IL-6 expression and disease severity and prognosis of multiple myeloma.

Keywords: Multiple myeloma, Vascular endothelial growth factor, Microvessel count, Interleukin-6,