Central nervous system hemangioblastomas in von Hippel-Lindau disease: Total growth rate and risk of developing new lesions not associated with circulating VEGF levels.

Abstract

Hemangioblastomas of the central nervous system are a prominent feature of von Hippel-Lindau-disease (vHL). Hemangioblastomas are known to secrete vascular endothelial growth factor (VEGF), suggesting a potential role of VEGF as a biomarker for tumor growth. Plasma VEGF samples from 24 patients with von Hippel-Lindau disease were analyzed by solid-phase proximity ligation assay (PLA). Levels were monitored over time together with numeric and volumetric CNS tumor burden, and compared to plasma VEGF levels in healthy controls. The mean yearly progression in tumor volume was 65.5%. Yearly risk of developing one or several new CNS tumor(s) was 50%. No significant correlation between tumor burden and levels of VEGF was seen. VEGF levels in patients (31.55-92.04; mean 55.83, median 56.41) as measured by immunodetection in a solid-phase PLA did not differ significantly from controls (37.38-104.56; mean 58.89, median 54.12) (p = 0,266). The increase in total CNS tumor volume in vHL occurred in a saltatory manner. The risk of developing a new lesion was 50% per year. We found no evidence for VEGF secretion from CNS hemangioblastomas in vHL in circulating blood. Other potential biomarkers should be explored to assess progression of tumor burden in vHL.