Ki-67 and Vascular Endothelial Growth Factor Expression in Intracranial Meningiomas in Dogs |
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Authors: | L.A. Matiasek S.R. Platt V. Adams T.J. Scase D. Keys J. Miller F. Adamo S. Long K. Matiasek |
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Affiliation: | Centre for Small Animal Studies, Animal Health Trust, Newmarket, UK;;Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Georgia, GA;;Department of Veterinary Medicine, University of Cambridge, Cambridge, UK;;Bay Area Veterinary Specialists, San Leandro, CA;;University of Pennsylvania, Philadelphia, PA;and;Department for Veterinary Neuropathology, LMU Munich, Munich, Germany |
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Abstract: | Background: Tumor proliferation in human intracranial meningiomas can be defined by the reactivity of the monoclonal antibody MIB-1 to the Ki-67 antigen. Vascular endothelial growth factor (VEGF), a pro-angiogenic factor, is a predictive marker for survival of dogs with intracranial meningiomas. Hypothesis: Ki-67 is expressed in canine intracranial meningiomas and is associated with VEGF expression. Ki-67 expression is a prognostic marker for patient outcome. Animals: Seventy client-owned dogs with WHO grade I intracranial meningiomas. Methods: Retrospective study assessing the degree of immunostaining for Ki-67 by MIB-1 and VEGF expression in intracranial meningioma tissue from dogs. MIB-1 Labeling Index (LI) was calculated with Image J NIH-software. Extent, intensity, and distribution of VEGF-expression was assessed semiquantitatively. Cross tabulations with Fisher's exact tests and nonparametric Spearman's rank correlations were performed to identify associations between VEGF expression and MIB-1 LI. Fifteen dogs underwent postsurgical radiotherapy and were included in survival analysis. The effect of MIB-1 LI on survival was examined by Kaplan-Meier and Cox proportional hazards regression procedures. Results: Ki-67 staining was positive in 91% (64/70) and VEGF expression was detected in 96% (67/70). There was no significant association between VEGF expression and MIB-1 LI. MIB-1 LI was not associated with survival. Conclusions and Clinical Importance: MIB-1 antibody can be used to document cell proliferation in intracranial meningiomas in dogs, but does not predict outcome. No association between VEGF as a marker of angiogenesis and tumor proliferation was found. Angiogenesis might be a more important predictor of meningioma activity in dogs than is Ki-67. |
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Keywords: | Canine Intracranial meningioma Ki-67 Survival VEGF |
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